# JavaScript basic - Exercises, Practice, Solution

## JavaScript basic [80 exercises with solution]

[An editor is available at the bottom of the page to write and execute the scripts.]

1. Write a JavaScript program to display the current day and time in the following format.  Go to the editor
Sample Output : Today is : Friday.
Current time is : 4 PM : 50 : 22
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2. Write a JavaScript program to print the contents of the current window.  Go to the editor
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3. Write a JavaScript program to get the current date.  Go to the editor
Expected Output :
mm-dd-yyyy, mm/dd/yyyy or dd-mm-yyyy, dd/mm/yyyy
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4. Write a JavaScript program to find the area of a triangle where lengths of the three of its sides are 5, 6, 7.  Go to the editor
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5. Write a JavaScript program to rotate the string 'w3resource' in right direction by periodically removing one letter from the end of the string and attaching it to the front.  Go to the editor
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6. Write a JavaScript program to determine whether a given year is a leap year in the Gregorian calendar.  Go to the editor
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7. Write a JavaScript program to find 1st January is being a Sunday between 2014 and 2050.  Go to the editor
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8. Write a JavaScript program where the program takes a random integer between 1 to 10, the user is then prompted to input a guess number. If the user input matches with guess number, the program will display a message "Good Work" otherwise display a message "Not matched".  Go to the editor
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9. Write a JavaScript program to calculate days left until next Christmas.  Go to the editor
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10. Write a JavaScript program to calculate multiplication and division of two numbers (input from user).  Go to the editor
Sample form :

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11. Write a JavaScript program to convert temperatures to and from Celsius, Fahrenheit.  Go to the editor
[ Formula : c/5 = (f-32)/9 [ where c = temperature in Celsius and f = temperature in Fahrenheit ]
Expected Output :
60°C is 140 °F
45°F is 7.222222222222222°C
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12. Write a JavaScript program to get the website URL (loading page).  Go to the editor
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13. Write a JavaScript exercise to create a variable using a user-defined name.  Go to the editor
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14. Write a JavaScript exercise to get the extension of a filename.  Go to the editor
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15. Write a JavaScript program to get the difference between a given number and 13, if the number is greater than 13 return double the absolute difference.  Go to the editor
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16. Write a JavaScript program to compute the sum of the two given integers. If the two values are same, then returns triple their sum.  Go to the editor
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17. Write a JavaScript program to compute the absolute difference between a specified number and 19. Returns triple their absolute difference if the specified number is greater than 19.  Go to the editor
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18. Write a JavaScript program to check two given numbers and return true if one of the number is 50 or if their sum is 50.  Go to the editor
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19. Write a JavaScript program to check a given integer is within 20 of 100 or 400.  Go to the editor
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20. Write a JavaScript program to check from two given integers, if one is positive and one is negative.  Go to the editor
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21. Write a JavaScript program to create a new string adding "Py" in front of a given string. If the given string begins with "Py" then return the original string.  Go to the editor
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22. Write a JavaScript program to remove a character at the specified position of a given string and return the new string.  Go to the editor
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23. Write a JavaScript program to create a new string from a given string changing the position of first and last characters. The string length must be greater than or equal to 1.  Go to the editor
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24. Write a JavaScript program to create a new string from a given string with the first character of the given string added at the front and back.  Go to the editor
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25. Write a JavaScript program check if a given positive number is a multiple of 3 or a multiple of 7.  Go to the editor
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26. Write a JavaScript program to create a new string from a given string taking the last 3 characters and added at both the front and back. The string length must be 3 or more.  Go to the editor
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27. Write a JavaScript program to check if a string starts with 'Java' and false otherwise.  Go to the editor
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28. Write a JavaScript program to check if two given integer values are in the range 50..99 (inclusive). Return true if either of them are in the said range.  Go to the editor
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29. Write a JavaScript program to check if three given integer values are in the range 50..99 (inclusive). Return true if one or more of them are in the said range.  Go to the editor
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30. Write a JavaScript program to check if a string "Script" presents at 5th (index 4) position in a given string, if "Script" presents in the string return the string without "Script" otherwise return the original one.  Go to the editor
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31. Write a JavaScript program to find the largest of three given integers.  Go to the editor
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32. Write a JavaScript program to find a value which is nearest to 100 from two different given integer values.  Go to the editor
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33. Write a JavaScript program to check if two numbers are in range 40..60 or in the range 70..100 inclusive.  Go to the editor
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34. Write a JavaScript program to find the larger number from the two given positive integers, the two numbers are in the range 40..60 inclusive.  Go to the editor
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35. Write a JavaScript program to check a given string contains 2 to 4 numbers of a specified character.  Go to the editor
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36. Write a JavaScript program to check if the last digit of the three given positive integers is same.  Go to the editor
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37. Write a JavaScript program to create new string with first 3 characters are in lower case. If the string length is less than 3 convert all the characters in upper case.  Go to the editor
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38. Write a JavaScript program to check the total marks of a student in various examinations. The student will get A+ grade if the total marks are in the range 89..100 inclusive, if the examination is "Final-exam." the student will get A+ grade and total marks must be greater than or equal to 90. Return true if the student get A+ grade or false otherwise.  Go to the editor
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39. Write a JavaScript program to compute the sum of the two given integers, If the sum is in the range 50..80 return 65 other wise return 80.  Go to the editor
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40. Write a JavaScript program to check from two given integers if either one is 8 or their sum or difference is 8.  Go to the editor
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41. Write a JavaScript program to check three given numbers, if the three numbers are same return 30 otherwise return 40 and if two numbers are same return 20.  Go to the editor
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42. Write a JavaScript program to check if three given numbers (integers) are increasing in strict mode and flag is "false", however if "true" is false the numbers will in soft mode.  Go to the editor
Note: Strict mode -> 10, 15, 31 : Soft mode -> 24, 22, 31 or 22, 22, 31
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43. Write a JavaScript program to check from three given numbers (non negative integers) that two or all of them have the same rightmost digit.  Go to the editor
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44. Write a JavaScript program to check from three given integers that if a number is greater than or equal to 20 and less than one of the others.  Go to the editor
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45. Write a JavaScript program to check two given integer values and return true if one of the number is 15 or if their sum or difference is 15.  Go to the editor
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46. Write a JavaScript program to check two given non-negative integers and if one of the number (not both) is multiple of 7 or 11.  Go to the editor
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47. Write a JavaScript program to check if a number in the range 40..10000 inclusive presents in two number (in same range).  Go to the editor
For example 40 presents in 400 and 4000
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48. Write a JavaScript program to reverse a given string.  Go to the editor
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49. Write a JavaScript program to replace every character in a given string with the character following it in the alphabet.  Go to the editor
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50. Write a JavaScript program to capitalize the first letter of each word of a given string.  Go to the editor
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51. Write a JavaScript program to convert a given number to hours and minutes.  Go to the editor
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52. Write a JavaScript program to convert the letters of a given string in alphabetical order.  Go to the editor
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53. Write a JavaScript program to check if the characters a and b are separated by exactly 3 places anywhere (at least once) in a given string.  Go to the editor
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54. Write a JavaScript program to count the number of vowels in a given string.  Go to the editor
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55. Write a JavaScript program to check if a given string contains equal number of p's and t's present.  Go to the editor
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56. Write a JavaScript program to divide two positive numbers and return a string with properly formatted commas.  Go to the editor
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57. Write a JavaScript program to create a new string of specified copies (positive number) of a given string.  Go to the editor
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58. Write a JavaScript program to create a new string of 4 copies of the last 3 characters of a given original string. The length of the given string must be 3 and above.  Go to the editor
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59. Write a JavaScript program to extract the first half of a string of even length.  Go to the editor
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60. Write a JavaScript program to create a new string without the first and last character of a given string.  Go to the editor
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61. Write a JavaScript program to concatenate two strings except their first character.  Go to the editor
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62. Write a JavaScript program to move last three character to the start of a given string. The string length must be greater or equal to three.  Go to the editor
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63. Write a JavaScript program to create a string using the middle three characters of a given string of odd length. The string length must be greater or equal to three.  Go to the editor
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64. Write a JavaScript program to concatenate two strings and return the result. If the length of the strings are not same then remove the characters from the longer string.  Go to the editor
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65. Write a JavaScript program to test if a string end with "Script". The string length must be greater or equal to 6.  Go to the editor
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66. Write a JavaScript program to display the city name if the string begins with "Los" or "New" otherwise return blank.  Go to the editor
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67. Write a JavaScript program to create a new string from a given string, removing the first and last characters of the string if the first or last character are 'P'. Return the original string if the condition is not satisfied.  Go to the editor
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68. Write a JavaScript program to create a new string using the first and last n characters from a given sting. The string length must be greater or equal to n.  Go to the editor
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69. Write a JavaScript program to compute the sum of three elements of a given array of integers of length 3.  Go to the editor
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70. Write a JavaScript program to rotate the elements left of a given array of integers of length 3.  Go to the editor
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71. Write a JavaScript program to check if 1 appears in first or last position of a given array of integers. The array length must be greater or equal to 1.  Go to the editor
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72. Write a JavaScript program to check if the first and last elements are equal of a given array of integers length 3.  Go to the editor
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73. Write a JavaScript program to reverse the elements of a given array of integers length 3.  Go to the editor
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74. Write a JavaScript program to find the larger value between the first or last and set all the other elements with that value. Display the new array.  Go to the editor
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75. Write a JavaScript program to create a new array taking the middle elements of the two arrays of integer and each length 3.  Go to the editor
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76. Write a JavaScript program to create a new array taking the first and last elements from a given array of integers and length must be greater or equal to 1.  Go to the editor
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77. Write a JavaScript program to test if an array of integers of length 2 contains 1 or a 3.  Go to the editor
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78. Write a JavaScript program to test if an array of integers of length 2 does not contain 1 or a 3.  Go to the editor
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79. Write a JavaScript program to test if a given array of integers contains 30 and 40 twice. The array length should be 0, 1, or 2.  Go to the editor
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80. Write a JavaScript program to swap the first and last elements of a given array of integers. The array length should be at least 1.  Go to the editor
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More to Come !

* To run the code mouse over on Output panel and click on 'Run with JS' button.*

Do not submit any solution at here, if you want to contribute go to the appropriate exercise page.