Practice 50 JavaScript String Programming Questions
Q1. Write a JavaScript program to reverse a given string.
Input: str = "hello"
Expected Output: olleh
Q2. Write a JavaScript program to check if a given string is a palindrome.
Input: str = "madam"
Expected Output: true
Q3. Write a JavaScript program to find the length of a string.
Input: str = "hello"
Expected Output: 5
Q4. Write a JavaScript program to convert a string to lowercase.
Input: str = "HELLO"
Expected Output: hello
Q5. Write a JavaScript program to convert a string to uppercase.
Input: str = "hello"
Expected Output: HELLO
Q6. Write a JavaScript program to count the number of vowels in a string.
Input: str = "hello"
Expected Output: 2
Q7. Write a JavaScript program to find the index of the first occurrence of a character in a string.
Input: str = "hello", char = "l"
Expected Output: 2
Q8. Write a JavaScript program to replace all occurrences of a substring in a string.
Input: str = "hello world", oldSub = "world", newSub = "universe"
Expected Output: hello universe
Q9. Write a JavaScript program to extract a substring from a string.
Input: str = "hello world", start = 0, length = 5
Expected Output: hello
Q10. Write a JavaScript program to check if a string contains a given substring.
Input: str = "hello world", subStr = "world"
Expected Output: true
Q11. Write a JavaScript program to concatenate two strings.
Input: str1 = "hello", str2 = "world"
Expected Output: helloworld
Q12. Write a JavaScript program to remove whitespace from the beginning and end of a string.
Input: str = " hello "
Expected Output: hello
Q13. Write a JavaScript program to check if a string starts with a given substring.
Input: str = "hello world", subStr = "hello"
Expected Output: true
Q14. Write a JavaScript program to check if a string ends with a given substring.
Input: str = "hello world", subStr = "world"
Expected Output: true
Q15. Write a JavaScript program to repeat a string a given number of times.
Input: str = "hello", times = 3
Expected Output: hellohellohello
Q16. Write a JavaScript program to check if a string contains only digits.
Input: str = "12345"
Expected Output: true
Q17. Write a JavaScript program to find the last index of a character in a string.
Input: str = "hello", char = "l"
Expected Output: 3
Q18. Write a JavaScript program to remove a specific character from a string.
Input: str = "hello", charToRemove = "l"
Expected Output: heo
Q19. Write a JavaScript program to convert a string into an array of words.
Input: str = "hello world"
Expected Output: ["hello", "world"]
Q20. Write a JavaScript program to check if a string is empty.
Input: str = ""
Expected Output: true
Q21. Write a JavaScript program to find the first non-repeating character in a string.
Input: str = "swiss"
Expected Output: w
Q22. Write a JavaScript program to split a string into an array of characters.
Input: str = "hello"
Expected Output: ["h", "e", "l", "l", "o"]
Q23. Write a JavaScript program to check if a string is a valid email address.
Input: email = "test@example.com"
Expected Output: true
Q24. Write a JavaScript program to check if a string is a valid phone number (US format).
Input: phone = "(123) 456-7890"
Expected Output: true
Q25. Write a JavaScript program to capitalize the first letter of each word in a string.
Input: str = "hello world"
Expected Output: Hello World
Q26. Write a JavaScript program to find the number of words in a string.
Input: str = "hello world"
Expected Output: 2
Q27. Write a JavaScript program to find the longest word in a string.
Input: str = "hello to the world"
Expected Output: hello
Q28. Write a JavaScript program to find the shortest word in a string.
Input: str = "hello to the world"
Expected Output: to
Q29. Write a JavaScript program to remove all digits from a string.
Input: str = "hello123world456"
Expected Output: helloworld
Q30. Write a JavaScript program to check if a string is a valid URL.
Input: url = "https://www.example.com"
Expected Output: true
Q31. Write a JavaScript program to check if a string contains only alphabets.
Input: str = "hello"
Expected Output: true
Q32. Write a JavaScript program to find the number of occurrences of a character in a string.
Input: str = "hello", char = "l"
Expected Output: 2
Q33. Write a JavaScript program to remove all vowels from a string.
Input: str = "hello"
Expected Output: hll
Q34. Write a JavaScript program to check if a string is a valid hexadecimal color code.
Input: color = "#FF5733"
Expected Output: true
Q35. Write a JavaScript program to escape special characters in a string.
Input: str = "hello (world)"
Expected Output: hello \(world\)
Q36. Write a JavaScript program to compare two strings.
Input: str1 = "hello", str2 = "world"
Expected Output: false
Q37. Write a JavaScript program to trim a string to a specified length.
Input: str = "hello world", length = 5
Expected Output: hello
Q38. Write a JavaScript program to repeat a string until a specified length.
Input: str = "ab", length = 7
Expected Output: abababa
Q39. Write a JavaScript program to insert a substring into a string at a given position.
Input: str = "hello world", subStr = "beautiful ", position = 6
Expected Output: hello beautiful world
Q40. Write a JavaScript program to check if a string contains only whitespace characters.
Input: str = " "
Expected Output: true
Q41. Write a JavaScript program to find the ASCII value of a character.
Input: char = "A"
Expected Output: 65
Q42. Write a JavaScript program to convert a string to an array of individual words.
Input: str = "hello world"
Expected Output: ["hello", "world"]
Q43. Write a JavaScript program to find if a string is a substring of another string.
Input: str = "hello world", subStr = "world"
Expected Output: true
Q44. Write a JavaScript program to get a string with only the first letter of each word capitalized.
Input: str = "hello world"
Expected Output: Hello World
Q45. Write a JavaScript program to find the position of the second occurrence of a character in a string.
Input: str = "hello", char = "l"
Expected Output: 3
Q46. Write a JavaScript program to convert a string to a number.
Input: str = "12345"
Expected Output: 12345
Q47. Write a JavaScript program to get a string with each word reversed.
Input: str = "hello world"
Expected Output: olleh dlrow
Q48. Write a JavaScript program to get a string without the first and last characters.
Input: str = "hello"
Expected Output: ell
Q49. Write a JavaScript program to check if a string contains only non-special characters.
Input: str = "hello123"
Expected Output: true
Q50. Write a JavaScript program to count the number of words starting with a particular letter in a string.
Input: str = "hello world, how are you", letter = "h"
Expected Output: 3