W3cubDocs

/JavaScript

Subtraction assignment

The subtraction assignment operator (-=) subtracts the value of the right operand from a variable and assigns the result to the variable.

Syntax

Operator: x -= y
Meaning:  x  = x - y

Examples

Using subtraction assignment

// Assuming the following variable
//  bar = 5

bar -= 2     // 3
bar -= 'foo' // NaN

Specifications

Browser compatibility

No compatibility data found. Please contribute data for "javascript.operators.subtraction_assignment" (depth: 1) to the MDN compatibility data repository.

See also

© 2005–2018 Mozilla Developer Network and individual contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://wiki.developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Subtraction_assignment