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JavaScript: Missing number from an array

JavaScript Math: Exercise-83 with Solution

Write a JavaScript program to find the missing number in a given array. There are no duplicates in the list.

Test Data:
([1,2,3,5,6,7]) -> 4
([2,3,4,5]) -> 1

Sample Solution:

HTML Code:

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <title>JavaScript program to missing number from an array</title>
</head>
<body>

</body>
</html>

JavaScript Code:

function test(nums) {
  for (let n = 1; n<= nums.length + 1; n++) {
    if (nums.indexOf(n) === -1) 
      return n;
  }
}

nums = [1,2,3,5,6,7]
console.log("nums = "+nums)
console.log("Missing number of the said array: "+test(nums));
nums = [2,3,4,5]
console.log("nums= "+nums)
console.log("Missing number of the said array: "+test(nums));

Sample Output:

nums = 1,2,3,5,6,7
Missing number of the said array: 4
nums= 2,3,4,5
Missing number of the said array: 1

Flowchart:

JavaScript: Missing number from an array.

Live Demo:

See the Pen javascript-math-exercise-83 by w3resource (@w3resource) on CodePen.


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Next: Sum of the Two highest Numbers

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