For consistency single-quotes (') are preferred to double-quotes ("). This is helpful when creating strings that include HTML.

Noncompliant Code Example

var firstParameter = "something";

Compliant Solution

var firstParameter = 'something';

Exceptions

JSX code and strings that contain quotes are ignored.

let heSaid = "Then he said 'What?'."  // ignored
let sheSaid = '"Whatever!" she replied.'  // ignored