Summary

A value representing the positive Infinity value.

Description

The value of Number.POSITIVE_INFINITY is the same as the value of the global object's Infinity property.

This value behaves slightly differently than mathematical infinity:

• Any positive value, including POSITIVE_INFINITY, multiplied by POSITIVE_INFINITY is POSITIVE_INFINITY.
• Any negative value, including NEGATIVE_INFINITY, multiplied by POSITIVE_INFINITY is NEGATIVE_INFINITY.
• Zero multiplied by POSITIVE_INFINITY is NaN.
• NaN multiplied by POSITIVE_INFINITY is NaN.
• POSITIVE_INFINITY, divided by any negative value except NEGATIVE_INFINITY, is NEGATIVE_INFINITY.
• POSITIVE_INFINITY, divided by any positive value except POSITIVE_INFINITY, is POSITIVE_INFINITY.
• POSITIVE_INFINITY, divided by either NEGATIVE_INFINITY or POSITIVE_INFINITY, is NaN.
• Any number divided by POSITIVE_INFINITY is Zero.

Several JavaScript methods (such as the Number constructor, parseFloat, and parseInt) return NaN if the value specified in the parameter is significantly higher than Number.MAX_VALUE.

You might use the Number.POSITIVE_INFINITY property to indicate an error condition that returns a finite number in case of success. Note, however, that isFinite would be more appropriate in such a case.

Example

In the following example, the variable bigNumber is assigned a value that is larger than the maximum value. When the if statement executes, bigNumber has the value "Infinity", so bigNumber is set to a more manageable value before continuing.

var bigNumber = Number.MAX_VALUE * 2
if (bigNumber == Number.POSITIVE_INFINITY) {
 bigNumber = returnFinite();
}

See Also

Infinity, NEGATIVE_INFINITY, isFinite