Number.POSITIVE_INFINITY

The same as the value of the global Infinity property.

The Number.POSITIVE_INFINITY 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.
• Any positive number divided by POSITIVE_INFINITY is positive zero (as defined in IEEE 754).
• Any negative number divided by POSITIVE_INFINITY is negative zero (as defined in IEEE 754.
• 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.
• Number.POSITIVE_INFINITY > x is true for any number x that isn't POSITIVE_INFINITY.

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 NaN would be more appropriate in such a case.

Because POSITIVE_INFINITY is a static property of Number, you always use it as Number.POSITIVE_INFINITY, rather than as a property of a number value.

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.

let bigNumber = Number.MAX_VALUE * 2;

if (bigNumber === Number.POSITIVE_INFINITY) {
  bigNumber = returnFinite();
}

• Number.NEGATIVE_INFINITY
• Number.isFinite()
• Infinity
• isFinite()