Convert a negative number to positive in JavaScript

Last Updated : 29 May, 2019

We can convert a negative number to a positive number in javascript by the methods described below.

Method 1: This is a general method in which we will first check whether the number is already positive or negative, if the number is negative then we will multiply the number with -1 to make it positive.

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Syntax:

if (a < 0) {
    a = a * -1;
}

Example: Below is the implementation of the above approach:

<script>
    // Javascript script 
    // to convert negative number
    // to positive number
  
    // Function to convert
    // given number to 
    // positive number
    function convert_positive(a) {
        // Check the number is negative
        if (a < 0) {
            // Multiply number with -1
            // to make it positive
            a = a * -1;
        }
        // Return the positive number
        return a;
    }
  
//Driver code
var n = -10;
var m = 5;
  
// Call function
n = convert_positive(n);
  
// Print result
document.write(n + "<br>");
  
// Call function
m = convert_positive(m);
  
// Print result
document.write(m + "<br>"); 
</script>

Output:

10
5

Method 2: In this method we will use Math.abs() function to convert negative number to positive number.

Syntax:

Math.abs(value)

Example: Below is the implementation of the above approach:

<script>
    // Javascript script 
    // to convert negative number
    // to positive number
      
      
    //Driver code
    var n = -30;
    var m = 15;
  
    // Using Math.abs() function
    n = Math.abs(n);
      
    // Print result
    document.write(n + "<br>");
      
    // Using Math.abs() function
    m = Math.abs(m);
      
    // Print result
    document.write(m + "<br>");
</script>                                    

Output:

30
15

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Convert a negative number to positive in JavaScript