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The grouping operator ( ) controls the precedence of evaluation in expressions.

Syntax

 ( )

Description

The grouping operator consists of a pair of parentheses around an expression or sub-expression to override the normal operator precedence so that expressions with lower precedence can be evaluated before an expression with higher priority. As it sounds it groups what's inside of the parentheses

Examples

Overriding multiplication and division first, then addition and subtraction to evaluate addition first.

var a = 1;
var b = 2;
var c = 3;

// default precedence
a + b * c     // 7
// evaluated by default like this
a + (b * c)   // 7

// now overriding precedence 
// addition before multiplication   
(a + b) * c   // 9

// which is equivalent to
a * c + b * c // 9

Specifications

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

Browser compatibility

FeatureChromeEdgeFirefoxInternet ExplorerOperaSafari
Basic support Yes Yes Yes Yes Yes Yes
FeatureAndroid webviewChrome for AndroidEdge mobileFirefox for AndroidIE mobileOpera AndroidiOS Safari
Basic support Yes Yes Yes Yes Yes Yes Yes

See also

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