NCERT Solutions for Class 11 Chapter 8 : Strings

The output of the given string operations are as follows:

1. Computer Science

2. Scienc

3. Cmue cec

4. e

5. Computer ScienceComputer Science

6. eniSrtpo

7. Computer Science

8. cOMPUTER sCIENCE

9. True

10. False

The output of the given string operations are as follows:

1. wz-1,new ganga nagar,new delhi

2. WZ-1,NEW GANGA NAGAR,NEW DELHI

3. 2

4. 5

5. 21

6. ['WZ-1', 'New Ganga Nagar', 'New Delhi']

7. ['WZ-1,New', 'Ganga', 'Nagar,New', 'Delhi']

8. WZ-1,Old Ganga Nagar,Old Delhi

9. ('WZ-1', ',', 'New Ganga Nagar,New Delhi')

10. Error .. Substring Not found

Program:
userInput = input("Write a sentence: ")
#Count the total number of characters in the text (including white spaces)which is the length of string
totalChar = len(userInput)
print("Total Characters: ",totalChar)
#Count the total number of alphabets,digit and special characters by looping through each character and incrementing the respective variable value
totalAlpha = totalDigit = totalSpecial = 0
for a in userInput:
    if a.isalpha():
        totalAlpha += 1
    elif a.isdigit():
        totalDigit += 1
    else:
        totalSpecial += 1

print("Total Alphabets: ",totalAlpha)
print("Total Digits: ",totalDigit)
print("Total Special Characters: ",totalSpecial)

#Count number of words (Assume that each word is separated by one space)
#Therefore, 1 space:2 words, 2 space:3 words and so on
totalSpace = 0
for b in userInput:
    if b.isspace():
        totalSpace += 1

print("Total Words in the Input :",(totalSpace + 1))

OUTPUT:
Write a sentence: Good Morning!
Total Characters: 13
Total Alphabets: 11
Total Digits: 0
Total Special Characters: 2
Total Words in the Input: 2 

Program:
#Changing a string to title case using title() function
def convertToTitle(string):
    titleString = string.title();
    print("The input string in title case is:",titleString)       
   
userInput = input("Write a sentence: ")
#Counting the number of space to get the number of words
totalSpace = 0
for b in userInput:
    if b.isspace():
        totalSpace += 1
#If the string is already in title case
if(userInput.istitle()):
    print("The String is already in title case")
#If the string is not in title case and consists of more than one word
elif(totalSpace > 0):
    convertToTitle(userInput)
#If the string is of one word only
else:
    print("The String is of one word only")

OUTPUT:
Write a sentence: good evening!
The input string in title case is: Good Evening!

Program 1:
#deleteChar function to delete all occurrences of char from string using replace() function
def deleteChar(string,char):
    #each char is replaced by empty character
    newString = string.replace(char,'')
    return newString

userInput = input("Enter any string: ")
delete = input("Input the character to delete from the string: ")

newStr = deleteChar(userInput,delete)

print("The new string after deleting all occurrences of",delete,"is: ",newStr)

OUTPUT:
Enter any string: Good Morning!
Input the character to delete from the string: o
The new string after deleting all occurrences of o is: Gd Mrning!


Program 2:
#deleteChar function to delete all occurrences of char from string without using replace() function
def deleteChar(string,char):
    newString = ''
    #Looping through each character of string
    for a in string:
    #if character matches, replace it by empty string
        if a == char:
    #continue
            newString += ''
        else:
            newString += a
    return newString

userInput = input("Enter any string: ")
delete = input("Input the character to delete from the string: ")

newStr = deleteChar(userInput,delete)

print("The new string after deleting all occurrences of",delete,"is: ",newStr)

OUTPUT:
Enter any string: Good Evening!
Input the character to delete from the string: o
The new string after deleting all occurrences of o is: Gd Evening!

Program:
#sumDigit function to sum all the digits
def sumDigit(string):
    sum = 0
    for a in string:
    #Checking if a character is digit and adding it
        if(a.isdigit()):
            sum += int(a)
    return sum
userInput = input("Enter any string with digits: ")
#Calling the sumDigit function
result = sumDigit(userInput)
#Printing the sum of all digits
print("The sum of all digits in the string '",userInput,"' is:",result)

OUTPUT:
Enter any string with digits: The cost of this table is Rs. 3450
The sum of all digits in the string ' The cost of this table is Rs. 3450 ' is: 12

Program:
#replaceChar function to replace space with hyphen
def replaceChar(string):
    return string.replace(' ','-')

userInput = input("Enter a sentence: ")

#Calling the replaceChar function to replace space with hyphen
result = replaceChar(userInput)

#Printing the modified sentence
print("The new sentence is:",result)

OUTPUT:
Enter a sentence: Python has several built-in functions that allow us to work with strings.
The new sentence is: Python-has-several-built-in-functions-that-allow-us-to-work-with-strings.
The same task can also be accomplished without using the string.replace() function. The program for the same can be written as :
Program:
#replaceChar function to replace space with hyphen
def replaceChar(string):
    newString = ''
    #Looping through each character of string
    for a in string:
        #if char is space, replace it with hyphen
        if a == ' ':
            newString += '-'
        #else leave the character as it is
        else:
            newString += a
    return newString

userInput = input("Enter a sentence: ")

#Calling the replaceChar function to replace space with hyphen
result = replaceChar(userInput)

#Printing the modified sentence
print("The new sentence is:",result)

OUTPUT:
Enter a sentence: Python has several built-in functions that allow us to work with strings.
The new sentence is: Python-has-several-built-in-functions-that-allow-us-to-work-with-strings.