Determine Absolute Value

By Stephen Bucaro

The absolute value is simply the value without a sign, for example the absolute value of 4, or +4, is the same as the absolute value of -4: 4. If you are creating an application that requires the absolute value of a number, use the Java Script Math.abs method.

For example if you are designing a graphics application that lets the user draw a horizontal line on the screen and you want to display the length of the line in the applications status bar.

If the user draws a line from point a = 100 pixels to point b = 50 pixels, we can subtract a - b to get the line length of 50 pixels. But what if the user draws a line from point a = 50 pixels to point b = 100 pixels? Subtracting a - b = -50 pixels. A line length of -50 pixels is a little confusing to the user.

We can solve that problem by passing the subtract statement to the Math.abs method as shown below.

var length = Math.abs(a - b);

The Math.abs method will always return the result as an unsigned number.