UP Board Solutions Class 10 Computer Science Chapter 8 Subscripted Variables

Subscripted Variables Long Answer Type Questions (8 Marks)

Question 1. What are subscripted variables? What is an Array? Explain. Or What is an Array? What are its different types? Explain. Or Explain the subscripted variable.
Answer: Subscript: A subscript may be a numeric constant or an integer-valued variable, is enclosed in parenthesis which identifies the position of a given element in the array. For example, the first element of array stu_age (containing the value 14) is referred to as stu_age [0]. Similarly, stu_age [1] = 16 stu_age [2] = 18 stu_age [3] = 17 stu_age [4] = 15 Here, 0, 1, 2, 3, 4 within parenthesis are known as subscript. In 'C' first element is in the 0th place and last element in the (n -1)th place in the array of n elements.
Subscripted Variable: A variable with a subscript is known as subscripted variable and it refers to one value in the array, e.g., stu_age [0], stu_age [1], etc. Declaration of an Array: As you know that all variables in 'C' must be declared before use, hence, we must declare the array. It is done at the beginning of the function main () with data type and size. Syntax: datatype name [size]; Example: int stu_age [5];
This statement states that stu_age is an array of 5 integers (Number of elements). This statement reserves enough memory for stu_age to hole 5 integers. Once the declaration is made, stu_age [0] refers to the first integer in the array, stu_age [1] refers to the second integer in the array and so on.
ℹ️ चित्र व्याख्या (Diagram Explanation): यह आरेख एक सरणी की घोषणा के सिंटैक्स को दर्शाता है। यह दर्शाता है कि एक सरणी में डेटा प्रकार, सरणी का नाम और उसकी निर्धारित संख्या (आकार) कैसे शामिल होती है, जैसे `int Stu age [5]`।
In simple words: Subscripted variables are used to access specific elements within an array, like `stu_age[0]` for the first element. An array is a collection of similar data types stored under a single name, declared with a specific data type and size.

🎯 Exam Tip: Clearly define subscripted variables and arrays, and provide a syntax example for array declaration, as this demonstrates fundamental programming knowledge.

Question 2. (a) Explain the following with reference to 'C' language: (i) Data Type (ii) Variables. (b) What are the various arithmetic operators available in 'C' language? Explain with example.
Answer: (a) (i) Data Type: A data type decides the amount of memory to be allocated to a variable to store a particular type of data. To allocate memory for a particular piece of data, we have to declare a variable of a particular data type. The variable declaration means that some memory is allocated and that portion of memory will be referred to by the variable name. Data types, which are commonly used in programming tools can be classified as :
• Numeric: Stores numeric value.
• Alpha Numeric: Stores descriptive information.
A numeric data type is called int: Similarly, an alpha-numeric data type is named char in C.
(ii) Variables: A variable is a name that represents a number or a string. Each numeric variable must consist of a letter or a letter followed by an integer. All variables that are to be used in the program must be declared prior to their use. Declaring a variable means defining a name and a data type of a variable. Every variable declaration is terminated by a semicolon. Variable names must begin with an alphabet. The first character may be followed by a sequence of letters or digits and can also include the special character 'Underscore'.
(b) Arithmetical Operators: Operators that perform mathematical operations are called Arithmetical operators. These operators form a mathematical expression using operands along- with. There are five types of arithmetical operands available in C++ which are as follows:
(i) Add (+): To perform addition of operands. These operands can either be literal, identifier or combination of both. e.g.: a + b
2 + 2
x + 2
(ii) Subtract (-): In order to perform subtraction, operands can be literal, identifier or combination of both. e.g.: x - y
15 - 5
A - 10
(iii) Multiply (*): This operator performs multiplication on operands. e.g.: y * z
15 * 32
A * 25
(iv) Divide (/): It is used to perform division of the two operands. e.g. A/B
25/5
X/2
(v) Exponentiation (%): It is a modulus operator and returns the remainder of the division. A / operator returns the quotient after the division of operands and a modulus operator returns the remainder after division. e.g. 10 % 3
X % 2
In simple words: Data types define the kind of data a variable can hold (like numbers or characters) and how much memory it needs. Variables are named storage locations that hold specific data. Arithmetic operators like +, -, *, /, and % perform basic mathematical calculations on these variables.

🎯 Exam Tip: When explaining data types and variables, provide a clear definition and mention their declaration. For arithmetic operators, list each operator with its function and a distinct example to illustrate its use.

Question 3. What do you mean by sorting? Define two methods of sorting. Or Give names of the main methods of sorting and explain any one method with an example.
Answer: Sorting: Sorting is the process of arranging the data or information in some logical order. This logical order may be ascending or descending in case of numeric values or dictionary order in case of alphanumeric values. For example: Suppose an unsorted array X of ten numeric values.
ℹ️ चित्र व्याख्या (Diagram Explanation): यह आरेख एक असॉर्टेड सरणी को दिखाता है जिसमें संख्याएँ किसी विशेष क्रम में नहीं हैं, फिर उसी सरणी को आरोही (सबसे छोटे से सबसे बड़े) और अवरोही (सबसे बड़े से सबसे छोटे) क्रम में सॉर्ट करके दिखाता है।
There are some methods of sorting the data of an array.
1. Insertion sorting
2. Bubble sorting
3. Selection sorting.
Insertion Sorting: This process uses only one array and requires (N - 1) passes and total comparison required are N (N - I)/2 to sort this array. The processing of sorting in ascending order is as follows: Suppose an unsorted array A is
This array has 6 elements, so it will complete the sorting in 5 passes (N - 1
\( \implies \) 6 - 1 = 5)
ℹ️ चित्र व्याख्या (Diagram Explanation): यह आरेख 'इन्सर्शन सॉर्टिंग' के पहले पास को दर्शाता है, जिसमें एक असॉर्टेड डेटासेट (71, 16, 12, 84, 96, 20) को लिया गया है। पहले पास के बाद, सरणी के तत्व आंशिक रूप से सॉर्ट होते हैं, जिसमें सबसे छोटा तत्व शीर्ष पर आ जाता है।
In this pass, the first element of an array should be compared with the rest of the array elements and placed the smallest element on top in ascending order.
In simple words: Sorting is the process of arranging data in a specific order, either ascending or descending. Insertion sorting is a method that iterates through the array, taking elements one by one and inserting them into their correct sorted position within the already sorted part of the array.

🎯 Exam Tip: Define sorting clearly and list common sorting methods. When explaining a specific method like Insertion Sort, describe its mechanism, the number of passes, and how elements are compared and moved.

ℹ️ चित्र व्याख्या (Diagram Explanation): यह आरेख 'इन्सर्शन सॉर्टिंग' के दूसरे पास को दर्शाता है, जिसमें पहले पास से आंशिक रूप से सॉर्ट की गई सरणी (12, 71, 16, 84, 96, 20) ली गई है। इसमें और तुलनाएँ करके सरणी के तत्वों को उनके सही आरोही क्रम में व्यवस्थित किया जाता है।
Suppose an unsorted array A is
Now you will sort this array using bubble sort method. In this method also, sorting requires (N - 1) passes to sort the elements of the array.
ℹ️ चित्र व्याख्या (Diagram Explanation): यह आरेख 'बबल सॉर्ट' के पहले पास को दर्शाता है। यह एक असॉर्टेड सरणी (40, 30, 25, 20, 10) के तत्वों को क्रमिक रूप से तुलना करके और स्वैप करके सबसे छोटे तत्व (10) को शीर्ष पर लाता है, जिससे आंशिक रूप से सॉर्टेड तत्व बनते हैं।
ℹ️ चित्र व्याख्या (Diagram Explanation): यह आरेख 'बबल सॉर्ट' के दूसरे पास को दर्शाता है। पहले पास के बाद के आंशिक रूप से सॉर्ट किए गए तत्वों का उपयोग करके, यह प्रक्रिया जारी रहती है, तत्वों को तुलना करके और स्वैप करके उन्हें आरोही क्रम में व्यवस्थित किया जाता है।

Question 4. What is searching? Explain its mechanism. Or What is searching? Explain two searching techniques.
Answer: Searching: It refers to the process of finding the location of the given data element from a collection of data. The search is said to be successful if the given data element is found. There are two searching techniques :
1. Linear Search
2. Binary Search.
1. Linear Search: It is also known as sequential search. In sequential searching, a particular data item is searched sequentially, i.e., the desired data first compared with the first element then the second element of an array, and so on. Example: WAP in 'C' to find the given number in the given array of 10 numeric type values: Program :
#include
void main()
{
int A [10] = {10, 50, 6, 7, 20, 30, 15, 25, 80, 90},
int i, N;
printf ("Input the Number");
scanf("%d", &N);
for (i = 0; i < 10; i ++)
{
if (N = = A[i])
printf ("%d is present in list on %d position", N, i);
break;
}
printf ("N is not present");
}
2. Binary Search: In binary searching, the arranged data is divided into two parts. The particular data item to be searched is compared with the middle data item. If it is less than the middle data, then it means that the data item to be searched is present in the first half of the data item set. The loop will be created for only half of the total value, thus, it saves the computer time also. In a binary search, it is mandatory that the data be arranged in either ascending or descending order. Example: Given a sorted (ascending order) array A with elements and we want to search the element 15 in it by binary search.
Binary Search Method:
Given Array A
To start with, we take BEG = 0, END = 6, and compute location of the middle element as MID = (BEG + END)/2 = (0 + 6)/2 = 3.
Since, A[MID] i.e., A[3] \( \neq \) 15, and BEG < END. We start next iteration. As A[MID] = 20 > 15, therefore, we take END = MID -1=3-1=2, where BEG remains unchanged. MID = (BEG + END)/2 = (0 + 2)/2 = 1 Since, A[MID] i.e., A[1] \( \neq \) 15, and BEG < END. We start the next iteration. As A[MID] = 10 < 15, therefore, we take BEG = MID + 1 = 1 + 1 = 2, where END remains unchanged; since BEG = END, again compute location of the middle element as MID = (BEG + END)/2 = (2 + 2)/2 = 2 Since A[MID] i.e., A[2] = 15, the search terminates with success.
In simple words: Searching is the process of finding a specific data element within a collection. Linear search checks elements one by one from the beginning. Binary search, applicable only on sorted data, repeatedly divides the search interval in half to find the element much faster.

🎯 Exam Tip: Clearly define searching and differentiate between Linear and Binary search. For Linear Search, a C program example is excellent. For Binary Search, emphasize the requirement for sorted data and explain the divide-and-conquer approach.

Question 5. What do you mean by Array? Define different types of array. Or What do you understand by Array? What are its different types? Describe each of them. Or What do you understand by Array? Discuss one dimensional and two-dimensional array with example.
Answer: An array is the collection of numeric or string values in the form of LIST (single row) or TABLE (rectangular arrangements in the form of rows and columns). A single variable name is used to refer to the entire collection of items. 'C' language permits us to deal with many related data items as a group by means of the structure known as an array.
An array can be used to store integer, real or string values, but the values in a given array must be of the same type. That is, if an array is given a numeric variable name, a string data item cannot be entered to it, only numeric values are allowed. For example, suppose that there are five test scores 15, 25, 35, 81, 75 to be stored. The scores could be put in an array called TEST. This array can be represented in memory as such.
ℹ️ चित्र व्याख्या (Diagram Explanation): यह आरेख दिखाता है कि मेमोरी में 'TEST' नामक सरणी में पाँच पूर्णांक मान (15, 25, 35, 81, 75) कैसे संग्रहीत किए जाते हैं। प्रत्येक मान को एक विशिष्ट सूचकांक ([0] से [4]) के साथ एक सरणी तत्व के रूप में दर्शाया गया है।
There are two types of array.
1. Single-dimensional array: It is a collection of numeric or string values in the form of a list. This is also known as single subscript variables because these variables have one subscript only e.g. int a[10].
2. Multi-dimensional array: It is defined in the same manner as a single-dimensional array, except that a separate pair of square brackets are required for each subscript. It is the collection of numeric or string values in the form of TABLE e.g. A[5][6], B[2][3][2] etc.
In simple words: An array is a collection of similar data types stored under a single variable name. Single-dimensional arrays store data in a list format, while multi-dimensional arrays store data in a table format, using multiple subscripts.

🎯 Exam Tip: When defining an array, highlight its primary characteristics (collection of similar data types, single name). For types, clearly distinguish between single-dimensional and multi-dimensional arrays with appropriate syntax examples for each.

Question 6. WAP to sort the elements of an array in ascending order.
Answer:
#include
void main()
{
int A[100];
int n, i, j, temp;
printf ("Enter how many nos");
scanf ("%d", &n);
for (i = 0; i < n; i++)
{
scanf ("%d", &A[i]);
}
for (i=0; i < n - 1; i++)
{
for (j = 0; j < n + i; j++)
{
if (A [j+1] < A[j])
temp = A[j];
A[j] =A[j + 1];
A[j + 1] = temp;
}
}
for (i = 0; i < n; i++)
{
printf ("%d", A[i]);
}
}
In simple words: This C program sorts an array of numbers in ascending order using a nested loop approach, commonly known as Bubble Sort. It repeatedly steps through the list, compares adjacent elements, and swaps them if they are in the wrong order until the entire array is sorted.

🎯 Exam Tip: For sorting programs, ensure the code correctly implements a sorting algorithm (like Bubble Sort shown here). Pay attention to loop conditions, comparison logic, and the swapping mechanism for full marks.

Question 7. WAP to search the given number in the given array of 10 numeric type values:
Answer:
#include
void main ()
{
int A[10] = {10, 50, 20, 30, 6, 7, 8, 70, 90, 75};
int i, n;
printf ("input the number");
scanf ("%d", &n);
for (i = 0; i < 10; i++)
{
if (n == A[i])
printf ("%d is present in list on %d position", n, i);
break;
}
printf ("%d is not present", n)
}
In simple words: This C program performs a linear search to find a specific number within a predefined array. It iterates through each element of the array, comparing it with the target number until a match is found or the end of the array is reached.

🎯 Exam Tip: When writing a search program, ensure the search logic (e.g., linear traversal and comparison) is correct, and include output messages for both successful and unsuccessful search scenarios.

Subscripted Variables Short Answer Type Questions (4 Marks)

Question 1. What do you mean by subscript?
Answer: To gain access to a single element within the array, a subscript is used. A subscript may be a numeric constant or an integer-valued variable, is enclosed in parentheses which identify the position of a given element in the array. For example, the first element of array TEST (containing the value 15) is referred to as TEST(0). The second test score is as TEST[1], the third test score is as TEST[2], and so on. Therefore, the following statements are true: TEST[0] = 15 TEST[1] = 25 TEST[2] = 5 TEST[3] = 81 TEST[4] = 75 Here, 0, 1, 2, 3 and 4 within parentheses are known as a subscript.
In simple words: A subscript is a number or variable (enclosed in brackets) that indicates the position of a specific element within an array. It helps to uniquely identify and access individual data items in an array.

🎯 Exam Tip: Define subscript clearly and provide examples demonstrating how it is used to access array elements, highlighting its role in identifying positions.

Question 2. Define the term List and Table.
Answer: An array is a collection of numeric or string values in the form of LIST or TABLE. LIST: List is a kind of arrangement in which values are arranged either in horizontal form or vertical form in a sequential row. e.g.,
TABLE: Table is a rectangular arrangement of values in the form of rows and columns. e.g.,
ℹ️ चित्र व्याख्या (Diagram Explanation): यह आरेख एक 3x4 की आयताकार सरणी या तालिका को दर्शाता है जिसमें पंक्तियों और स्तंभों में पूर्णांक मान व्यवस्थित हैं। यह तालिका के प्रत्येक सेल में संख्याओं को व्यवस्थित रूप से दिखाता है।
In simple words: A List arranges values sequentially in a single row or column. A Table arranges values in a grid-like structure with both rows and columns. Both are ways to organize data in arrays.

🎯 Exam Tip: Differentiate between "List" and "Table" by explaining their structural arrangements for data, providing a simple example for each to illustrate the concept clearly.

Question 3. WAP to find the factorial of 'n'.
Answer:
#include
void main()
{
int n, i, fact = 1;
printf ("Enter the value for n");
scanf ("%d", &n);
for (i = 1; i <= n; i++)
{
fact = fact * i;
}
printf ("factorial of %d is %d", n, fact);
}
In simple words: This C program calculates the factorial of a given positive integer 'n'. It takes 'n' as input and then iteratively multiplies 'fact' by each number from 1 up to 'n' to compute the factorial.

🎯 Exam Tip: For factorial programs, ensure the loop iterates correctly from 1 to 'n' and that the `fact` variable is initialized properly (e.g., to 1). Handle edge cases like `n=0` (factorial is 1) if specifically asked.

Question 4. What is Binary Search?
Answer: In this method of searching, only sorted data can be used. Unsorted data cannot be used to apply this type of search. To do searching in Binary method, the sorted data is divided into two parts and the particular element is compared with the middle element. If found greater, the first and middle element is divided into two parts and their middle element is compared. And if found smaller, the middle and the last element is divided into two parts and their middle element is compared. This process goes on until the search is completed. This method of search is quick and saves time. It is also known as Random search.
In simple words: Binary search is an efficient search algorithm that works on sorted data by repeatedly dividing the search interval in half. It compares the target value with the middle element to determine if the element is in the left or right half, narrowing down the search space quickly.

🎯 Exam Tip: Emphasize that binary search *requires* sorted data and explain the 'divide and conquer' strategy. Mention its efficiency in saving time compared to linear search.

Question 5. Write a short note on sorting?
Answer: It is easy to carry out different operations on the idea if it is arranged or in some order (ascending or descending). The process of arranging the data or information in some order (ascending or descending in case of numeric data and dictionary order in case of alphanumeric data) is called sorting. Example:
ℹ️ चित्र व्याख्या (Diagram Explanation): यह आरेख एक असॉर्टेड डेटा सूची (10, 5, 6, 7, 9, 4, 5) और उसी सूची को आरोही क्रम में सॉर्ट करने के बाद के परिणाम (4, 5, 5, 6, 7, 9, 10) को दर्शाता है। यह सॉर्टिंग प्रक्रिया का एक स्पष्ट उदाहरण है।
In simple words: Sorting is the process of arranging data, whether numeric or alphanumeric, into a specific logical order, typically ascending or descending. This organization makes data easier to analyze and process.

🎯 Exam Tip: Provide a concise definition of sorting, including both ascending and descending order for different data types. A simple example demonstrating before and after sorting can be very effective.

Question 6. Write a short note on searching? Or Differentiate between sequential and binary search.
Answer: Searching: Searching means finding an element from an array. It refers to the process of finding the location of a given data element from an array. For example: If you want to work on your computer notebook, you have to search for it for yourself. You can do searching by two methods:
1. Sequential Search: This search is also known as linear search because in this method to search an element from data source one has to compare particular data item with the first element than the second element and so on until the search is completed. Because of this sequential approach, it is known as sequential search. In this, if the element is found in the middle, search process terminates.
2. Binary Search: In this method of searching, only sorted data can be used, unsorted data cannot be used to apply this type of search. To do searching in Binary method, the sorted data is divided into two parts and the particular element is compared with the middle element. If found greater, the first and that middle element is divided into two parts and their middle element is compared. And if found smaller, the middle and the last element is divided into two parts and their middle element is compared. This process goes on until the search is completed. This method of search is quick and saves time. It is also known as Random search.
In simple words: Searching is the process of locating a specific item within a data collection. Sequential search checks each item one by one, while binary search (for sorted data) repeatedly halves the search space to find the item faster.

🎯 Exam Tip: Define searching and explain its purpose. For differentiating between sequential and binary search, highlight the need for sorted data in binary search and the difference in their approach (item-by-item vs. divide-and-conquer) and efficiency.

Subscripted Variables Very Short Answer Type Questions (2 Marks)

Question 1. From which element binary search starts searching in an array?
Answer: From the middle element, the binary search starts searching in an array.
In simple words: Binary search always begins its search by comparing the target element with the middle element of the array.

🎯 Exam Tip: Remember that binary search's efficiency comes from starting at the middle and halving the search space.

Question 2. What do you mean by sorting?
Answer: Sorting is the process of arranging the data in some order.
In simple words: Sorting is the act of organizing a collection of data into a specific logical sequence, like alphabetical or numerical order.

🎯 Exam Tip: A concise definition of sorting, focusing on arranging data in a specific order, is key.

Question 3. Is an array a collection of similar elements?
Answer: Yes, an array is a collection of similar elements.
In simple words: An array can only store elements of the same data type, ensuring uniformity in its collection.

🎯 Exam Tip: The homogeneity of elements is a fundamental characteristic of arrays; stating this clearly is important.

Question 4. What is the number of the first element in an array?
Answer: The first element in the array is numbered 0.
In simple words: In most programming languages, array indexing starts from zero, meaning the first element is at position 0.

🎯 Exam Tip: Always remember that array indexing is typically zero-based, making the first element at index 0.

Question 5. What are the different methods of sorting?
Answer: The different methods of sorting are:
1. Insertion
2. Bubble
3. Selection.
In simple words: Common sorting methods include Insertion Sort, which places elements into their correct position one by one; Bubble Sort, which repeatedly swaps adjacent elements; and Selection Sort, which finds the minimum element and places it at the beginning.

🎯 Exam Tip: Listing at least two or three common sorting methods is sufficient for this type of question.

Question 6. Arranging the data in some order is known as:
Answer: Sorting.
In simple words: The process of organizing data into a specific sequence, such as ascending or descending, is called sorting.

🎯 Exam Tip: This is a direct definition; ensuring the correct term "Sorting" is provided is crucial.

Question 7. Name two types of searching.
Answer: Sequential and Binary.
In simple words: Two primary methods for finding data are Sequential Search, which checks elements one by one, and Binary Search, which efficiently narrows down the search space in sorted data.

🎯 Exam Tip: Correctly naming Sequential (or Linear) Search and Binary Search is the expected answer.

Subscripted Variables Objective Type Questions (1 Marks)

Question 1. A double dimensional array is a collection of a numeric value in the form of: (a) TABLE (b) WAP (c) SORT (d) None of these.
Answer: (a) TABLE
In simple words: A two-dimensional array, often visualized as rows and columns, stores data in a tabular format.

🎯 Exam Tip: Recall that multi-dimensional arrays represent data in a table-like structure.

Question 2. Which of the following is not a character constant? (a) Sorry (b) Enter values of A, B, C. (c) 123.50 (d) All of the above.
Answer: (d) All of the above.
In simple words: A character constant typically represents a single character enclosed in single quotes. The given options are either strings (multiple characters) or a floating-point number, none of which are character constants.

🎯 Exam Tip: Understand the definition of a character constant (single character in single quotes) versus a string constant or numeric value.

Question 3. If x is an integer variable, x = will return a value: (a) 2.5 (b) 3 (c) 2 (d) 1
Answer: (b) 3
In simple words: When an integer variable is assigned a floating-point value, the decimal part is truncated, so 2.5 becomes 2, and the value is 3.

🎯 Exam Tip: Remember that integer variables only store whole numbers; any decimal part of an assigned value is truncated (not rounded).

Question 4. The maximum width of a ‘C' variable name can be: (a) 5 characters (b) 8 characters (c) 10 characters (d) 20 characters.
Answer: (b) 8 characters
In simple words: While modern C compilers allow longer variable names, traditionally and in many older C standards, only the first 8 characters of an identifier were guaranteed to be significant.

🎯 Exam Tip: While modern compilers are more flexible, be aware of traditional C standards regarding significant variable name length (often 8 characters).