1. Get the First and Last 2 Characters
Description: Write a JavaScript program to create a new string using the first 2 and last 2 characters of a given string. If the string length is less than 2, return an empty string.
Input: "JavaScript"
Expected Output: "Japt"
2. Find the Length of the Longest String in an Array
Description: Write a JavaScript program to find the length of the longest string from an array of strings.
Input:
["Java", "Programming", "Code"]Expected Output:
113. Repeat the Last Two Characters Four Times
Description: Write a JavaScript program to create a string made of four copies of the last two characters.
Input: "Coding"
Expected Output:
ngngngng4. Reverse a String if Its Length is a Multiple of 4
Description: Reverse the string only if its length is divisible by 4.
Input: "Code"
Expected Output:
edoC5. Count Occurrences of a Substring
Description: Count how many times a substring appears inside a string.
Input:
String: "banana"
Substring: "an"Expected Output:
26. Check Whether a Character is a Vowel or Consonant
Description: Determine whether a given alphabet is a vowel or consonant.
Input: "e"
Expected Output:
Vowel7. Find the Longest and Shortest Word
Description: Find the longest and shortest words in a sentence.
Input:
"I love learning JavaScript"Expected Output:
Longest: JavaScript
Shortest: I8. Find the Most Frequently Repeated Character
Description: Find the character with the highest frequency.
Input: "programming"
Expected Output:
g9. Calculate String Length Without Using length Property
Description: Find the length of a string using loop logic only.
Input: "JavaScript"
Expected Output:
1010. Replace Every Second Occurrence of a Character with ‘$’
Description: Replace every second occurrence of each repeated character with the $ symbol.
Input: "Programming"
Expected Output:
Prog$am$in$11. Swap the First and Last Character
Description: Exchange the first and last characters of the string.
Input: "JavaScript"
Expected Output:
tavaScripJ12. Swap the First and Last Character of Every Word
Description: Exchange the first and last character of each word in a sentence.
Input:
"Online Learning"Expected Output:
enliOn gearninL13. Count Vowels in Each Word
Description: Count vowels present in every word and display the result as an object.
Input:
"We are learning JavaScript"Expected Output:
{
We:1,
are:2,
learning:3,
JavaScript:3
}14. Repeat Vowels Three Times and Consonants Twice
Description: Repeat every vowel three times and every consonant twice.
Input: "Code"
Expected Output:
CCooodee15. Check Whether a String is a Palindrome
Description: Check whether the given string reads the same forwards and backwards.
Input: "madam"
Expected Output:
Palindrome16. Reverse the Entire String
Description: Reverse all characters of the string.
Input: "JavaScript"
Expected Output:
tpircSavaJ17. Calculate String Length
Description: Find the total number of characters in the string.
Input: "Programming"
Expected Output:
1118. Count Frequency of Every Character
Description: Count the occurrences of each character.
Input: "hello"
Expected Output:
{
h:1,
e:1,
l:2,
o:1
}19. Combine Two Strings
Description: Join two strings together.
Input:
"Hello"
"World"Expected Output:
HelloWorld20. Print Characters at Even Positions
Description: Display characters at even index positions.
Input: "JavaScript"
Expected Output:
JvSrp21. Check Whether the String Contains Numbers
Description: Determine whether the string contains any numeric digit.
Input: "Code123"
Expected Output:
Contains Number22. Count Total Vowels
Description: Count all vowels present in the string.
Input: "I love JavaScript"
Expected Output:
623. Count Total Consonants
Description: Count all consonants present in the string.
Input: "JavaScript"
Expected Output:
724. Print Characters at Odd Positions
Description: Display characters at odd index positions.
Input: "abcdefg"
Expected Output:
bdf25. Remove Duplicate Characters
Description: Remove duplicate characters while preserving the first occurrence.
Input: "programming"
Expected Output:
progamin26. Check Whether a String Contains Special Characters
Description: Write a JavaScript program to determine whether a given string contains any special characters.
Input:
"JavaScript@2025!"Expected Output:
Given string contains special characters.27. Exchange the First and Last Character of the Entire String
Description: Write a JavaScript program to swap the first and last character of the complete string.
Input:
"We are learning JavaScript"Expected Output:
"ee are learning JavaScripW"28. Convert All Characters to Uppercase
Description: Write a JavaScript program to convert all lowercase letters of a string into uppercase.
Input:
"I live in Pune"Expected Output:
"I LIVE IN PUNE"29. Remove Newline Characters
Description: Write a JavaScript program to remove newline (\n) characters from a string.
Input:
"Object Oriented Programming\n"Expected Output:
"Object Oriented Programming"30. Split and Join a String
Description: Write a JavaScript program to split a string into words and join them using a hyphen (-).
Input:
"Hello World"Expected Output:
["Hello", "World"]
"Hello-World"31. Format a Floating-Point Number
Description: Write a JavaScript program to display a floating-point number with exactly 3 decimal places and convert it into a string.
Input:
2.14652Expected Output:
"2.147"32. Convert Number Words into Digits
Description: Write a JavaScript program to convert number words into their corresponding numeric value.
Input:
"five four three two one"Expected Output:
5432133. Find the Position of a Word
Description: Write a JavaScript program to find the position of a specified word in a sentence.
Input:
Sentence: "I am solving string problems"
Word: "problems"Expected Output:
434. Count Occurrences of a Word
Description: Write a JavaScript program to count how many times a word appears in a sentence.
Input:
Sentence: "We are learning JavaScript and we are practicing daily"
Word: "are"Expected Output:
235. Find the Least Frequent Character
Description: Write a JavaScript program to identify the character with the lowest frequency in a string.
Input:
"abcdabdggfhf"Expected Output:
c36. Find Words Greater Than a Given Length
Description: Write a JavaScript program to display all words whose length is greater than the specified value.
Input:
Length: 3
Sentence: "We are learning JavaScript"Expected Output:
["learning", "JavaScript"]37. Get the First Four Characters
Description: Write a JavaScript program to extract the first four characters from a string.
Input:
"JavaScript"Expected Output:
"Java"38. Create a String Using the First Two and Last Two Characters
Description: Write a JavaScript program to create a new string using the first two and last two characters.
Input:
"JavaScript"Expected Output:
"Japt"39. Print the Mirror Image of a String
Description: Write a JavaScript program to display the mirror image (reverse) of a string.
Input:
"JavaScript"Expected Output:
"tpircSavaJ"40. Split a String on Vowels
Description: Write a JavaScript program to split a string wherever a vowel occurs.
Input:
"qwerty"Expected Output:
["qw", "rty"]41. Replace Multiple Words
Description: Write a JavaScript program to replace multiple words in a sentence with new words.
Input:
Sentence: "I am learning JavaScript at SQA Tools"
Replace:
JavaScript → JS
SQA Tools → AcademyExpected Output:
"I am learning JS at Academy"42. Replace Multiple Characters
Description: Write a JavaScript program to replace multiple characters in a string simultaneously.
Input:
String: "JavaScript"
Replace:
a → 1
t → 2
i → 3Expected Output:
"J1v1Scr3p2"43. Remove Empty Strings from an Array
Description: Write a JavaScript program to remove empty strings from an array of strings.
Input:
["JavaScript", "", "", "Programming"]Expected Output:
["JavaScript", "Programming"]44. Remove Punctuation
Description: Write a JavaScript program to remove all punctuation marks from a string.
Input:
"JavaScript: is great, for web development!"Expected Output:
"JavaScript is great for web development"45. Find Duplicate Characters
Description: Write a JavaScript program to display all duplicate characters in a string.
Input:
"hello world"Expected Output:
"lo"46. Check Whether One String is a Subset of Another
Description: Write a JavaScript program to determine whether all characters of one string exist in another string.
Input:
Main String: "iamlearningjavascript"
Subset String: "jscript"Expected Output:
true47. Sort Characters in a String
Description: Write a JavaScript program to sort all characters of a string in ascending order.
Input:
"xyabkmp"Expected Output:
"abkmpxy"48. Generate a Random Binary String
Description: Write a JavaScript program to generate a random binary string of the specified length.
Input:
8Expected Output:
1010011049. Check Whether a Substring Exists
Description: Write a JavaScript program to determine whether a given substring exists in a string.
Input:
String: "I live in Pune"
Substring: "live"Expected Output:
Yes50. Find Frequency of All Substrings
Description: Write a JavaScript program to calculate the frequency of every possible substring in a string.
Input:
"abab"Expected Output:
{
"a":2,
"ab":2,
"aba":1,
"abab":1,
"b":2,
"ba":1,
"bab":1
}51. Check Whether Two Strings are Rotations of Each Other
Description: Write a JavaScript program to check whether one string is a rotation of another string.
Input:
String 1: "ABCD"
String 2: "CDAB"Expected Output:
The strings are rotations of each other.52. Remove All Whitespaces from a String
Description: Write a JavaScript program to remove all whitespace characters from a string.
Input:
"JavaScript Programming Language"Expected Output:
"JavaScriptProgrammingLanguage"53. Capitalize the First Letter of Every Word
Description: Write a JavaScript program to convert the first letter of every word to uppercase.
Input:
"welcome to javascript programming"Expected Output:
"Welcome To Javascript Programming"54. Convert the First Letter of Every Word to Lowercase
Description: Write a JavaScript program to convert the first letter of every word to lowercase while keeping the remaining characters unchanged.
Input:
"Hello World JavaScript"Expected Output:
"hello world javascript"55. Find the ASCII Value of Each Character
Description: Write a JavaScript program to display the ASCII (Unicode) value of every character in a string.
Input:
"ABC"Expected Output:
A : 65
B : 66
C : 6756. Count the Number of Digits in a String
Description: Write a JavaScript program to count how many numeric digits are present in a string.
Input:
"Java123Script45"Expected Output:
557. Remove All Digits from a String
Description: Write a JavaScript program to remove all numeric digits from a string.
Input:
"Java123Script45"Expected Output:
"JavaScript"58. Replace Spaces with Hyphens
Description: Write a JavaScript program to replace every space in a string with a hyphen (-).
Input:
"I love JavaScript"Expected Output:
"I-love-JavaScript"59. Count the Number of Words in a Sentence
Description: Write a JavaScript program to count the total number of words in a sentence.
Input:
"JavaScript is easy to learn"Expected Output:
560. Find the Middle Character of a String
Description: Write a JavaScript program to display the middle character of a string. If the string length is even, display the two middle characters.
Input:
"Python"Expected Output:
"th"61. Remove the First Occurrence of a Character
Description: Write a JavaScript program to remove the first occurrence of a specified character from a string.
Input:
String: "programming"
Character: "r"Expected Output:
"pogramming"62. Remove the Last Occurrence of a Character
Description: Write a JavaScript program to remove the last occurrence of a specified character from a string.
Input:
String: "programming"
Character: "m"Expected Output:
"programing"63. Find All Positions of a Character
Description: Write a JavaScript program to display all index positions of a specified character.
Input:
String: "banana"
Character: "a"Expected Output:
[1, 3, 5]64. Find the First Non-Repeated Character
Description: Write a JavaScript program to find the first character that appears only once in a string.
Input:
"swiss"Expected Output:
"w"65. Find the First Repeated Character
Description: Write a JavaScript program to find the first character that appears more than once.
Input:
"programming"Expected Output:
"r"66. Reverse Every Word in a Sentence
Description: Write a JavaScript program to reverse every word individually without changing the word order.
Input:
"I love JavaScript"Expected Output:
"I evol tpircSavaJ"67. Reverse the Order of Words
Description: Write a JavaScript program to reverse the order of words in a sentence.
Input:
"I love JavaScript"Expected Output:
"JavaScript love I"68. Find the Longest Palindromic Word
Description: Write a JavaScript program to find the longest palindrome word from a sentence.
Input:
"madam level racecar apple"Expected Output:
"racecar"69. Count Uppercase and Lowercase Letters
Description: Write a JavaScript program to count the total number of uppercase and lowercase letters.
Input:
"JavaScript123"Expected Output:
Uppercase: 2
Lowercase: 870. Check Whether a String Starts and Ends with the Same Character
Description: Write a JavaScript program to determine whether the first and last characters of a string are the same.
Input:
"level"Expected Output:
Yes71. Remove Consecutive Duplicate Characters
Description: Write a JavaScript program to remove consecutive duplicate characters from a string.
Input:
"aabbbccdaa"Expected Output:
"abcda"72. Compress a String Using Character Count
Description: Write a JavaScript program to compress a string by replacing repeated characters with their frequency.
Input:
"aaabbcccc"Expected Output:
"a3b2c4"73. Expand a Compressed String
Description: Write a JavaScript program to expand a compressed string into its original form.
Input:
"a3b2c4"Expected Output:
"aaabbcccc"74. Find the Common Characters Between Two Strings
Description: Write a JavaScript program to display all common characters present in two strings.
Input:
String 1: "javascript"
String 2: "typescript"Expected Output:
"a, s, c, r, i, p, t"75. Remove Common Characters from Two Strings
Description: Write a JavaScript program to remove all common characters from two given strings.
Input:
String 1: "apple"
String 2: "ample"Expected Output:
String 1: "p"
String 2: "m"