JavaScript Math round()

Math.round() Syntax

The syntax of the Math.round() function is:

Math.round(x)

round(), being a static method, is called using the Math class name.

Math.round() Parameters

The Math.round() function takes in:

• x - A number

Return value from Math.round()

Math.round() returns the value of the number rounded to the nearest integer as follows:

• If the fractional portion > 0.5, x is rounded to integer with higher absolute value.
• If the fractional portion < 0.5, x is rounded to integer with lower absolute value.
• If the fractional portion = 0.5, x is rounded to the next integer in the direction of +∞.

Example: Using Math.round()

Output

2
10
5
-4
0
NaN

Note: Math.round() returns 0 for null rather than NaN.

Recommended readings:

• JavaScript Math trunc()
• JavaScript Math ceil()
• JavaScript Math floor()