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The Math.PI property represents the ratio of the circumference of a circle to its diameter, approximately 3.14159:

Math.PI=π3.14159\mathtt{\mi{Math.PI}} = \pi \approx 3.14159

Property attributes of Math.PI
Writable no
Enumerable no
Configurable no

Description

Because PI is a static property of Math, you always use it as Math.PI, rather than as a property of a Math object you created (Math is not a constructor).

Examples

Using Math.PI

The following function uses Math.PI to calculate the circumference of a circle with a passed radius.

function calculateCircumference(radius) {
  return Math.PI * (radius + radius);
}

calculateCircumference(1);  // 6.283185307179586

Specifications

Specification Status Comment
ECMAScript 1st Edition (ECMA-262) Standard Initial definition. Implemented in JavaScript 1.0.
ECMAScript 5.1 (ECMA-262)
The definition of 'Math.PI' in that specification.
Standard  
ECMAScript 2015 (6th Edition, ECMA-262)
The definition of 'Math.PI' in that specification.
Standard  
ECMAScript Latest Draft (ECMA-262)
The definition of 'Math.PI' in that specification.
Draft  

Browser compatibility

FeatureChromeEdgeFirefoxInternet ExplorerOperaSafari
Basic support Yes Yes1 Yes Yes Yes
FeatureAndroid webviewChrome for AndroidEdge mobileFirefox for AndroidOpera AndroidiOS SafariSamsung Internet
Basic support Yes Yes Yes4 Yes Yes Yes

See also

Tag del documento e collaboratori

Ultima modifica di: wbamberg,