toExponential

Summary

The toExponential() method formats a number to exponential notation.

Syntax

toExponential([ fractionDigits ])

fractionDigits

Optional. The number of digits after the decimal point. Must be in the range 0 - 20, inclusive.

Return Value

Returns a string representation of a number in exponential notation. The string contains one digit before the decimal point, and may contain fractionDigits digits after it.

If fractionDigits is not supplied, the toExponential method returns as many digits necessary to uniquely specify the number.

Examples

Using toExponential to format the text presentation of a number.

var pie = 3.14159;

pie.toPrecision();
// Returns: "3.14159e+0"

pie.toPrecision(3);
// Returns: "3.142e+0"

pie.toPrecision(1);
// Returns: "3.1e+0"

pie.toPrecision(0);
// Returns: "3e+0"

Remarks

Throws

RangeError when a fractionDigits outside the bounds of 0 - 20 (inclusive) was given.

See also

Other articles

• toFixed Method (Number)
• toPrecision Method (Number)
• toString Method (Number)

External resources

• toExponential(), by Mozilla Developer Network

Specification

15.7.4.6 Number.prototype.toExponential(fractionDigits)

ECMAScript® Language Specification Standard ECMA-262 5.1 Edition / June 2011

Attributions

• Microsoft Developer Network: Article