round

Rounds a number to the given number of decimal places. A negative precision rounds to tens, hundreds and so on: round(1234, -2) returns 1200.

Ties round half away from zero, so 0.5 becomes 1 and -0.5 becomes -1. This is a parity fix first and a precision helper second, because the three languages disagree natively — 0.5 gives 1 in JavaScript, 1 in Dart and 0 in Python; -1.5 gives -1, -2 and -2. Lodash also differs here: it sends ties toward positive infinity, so _.round(-0.5) is -0.

The value is shifted through its shortest string representation rather than multiplied by a power of ten, so the usual floating-point surprises do not happen: round(1.005, 2) returns 1.01, not 1, and round(2.675, 2) returns 2.68.

NaN and the infinities are returned as they are.

To round up or down instead of to the nearest value, use ceil and floor, which take the same arguments.

Parameters

Name	Type	Required	Default
value	numbernumint	●	–
The number to round.
precision	numberint	–	0
Number of decimal places to round to. Must be a whole number; a negative value rounds to tens, hundreds and so on.

Returns

number

num

int

Examples

round(0.5); // Returns 1
round(2.5); // Returns 3
round(-0.5); // Returns -1
round(-1.5); // Returns -2
round(1.005, 2); // Returns 1.01
round(2.675, 2); // Returns 2.68
round(1234, -2); // Returns 1200

round(0.5); // Returns 1
round(2.5); // Returns 3
round(-0.5); // Returns -1
round(-1.5); // Returns -2
round(1.005, 2); // Returns 1.01
round(2.675, 2); // Returns 2.68
round(1234, -2); // Returns 1200

round(0.5)  # Returns 1
round(2.5)  # Returns 3
round(-0.5)  # Returns -1
round(-1.5)  # Returns -2
round(1.005, 2)  # Returns 1.01
round(2.675, 2)  # Returns 2.68
round(1234, -2)  # Returns 1200