The ignoreCase property indicates whether or not the "i" flag is used with the regular expression. ignoreCase is a read-only property of an individual regular expression instance.
| Property attributes of RegExp.prototype.ignoreCase | |
|---|---|
| Writable | no | 
| Enumerable | no | 
| Configurable | yes | 
Description
The value of ignoreCase is a Boolean and true if the "i" flag was used; otherwise, false. The "i" flag indicates that case should be ignored while attempting a match in a string.
You cannot change this property directly.
Examples
Using ignoreCase
var regex = new RegExp('foo', 'i');
console.log(regex.ignoreCase); // true
Specifications
| Specification | Status | Comment | 
|---|---|---|
| ECMAScript 3rd Edition (ECMA-262) | Standard | Initial definition. Implemented in JavaScript 1.2. JavaScript 1.5: ignoreCaseis a property of aRegExpinstance, not theRegExpobject. | 
| ECMAScript 5.1 (ECMA-262) The definition of 'RegExp.prototype.ignoreCase' in that specification. | Standard | |
| ECMAScript 2015 (6th Edition, ECMA-262) The definition of 'RegExp.prototype.ignoreCase' in that specification. | Standard | ignoreCaseis now a prototype accessor property rather than an instance's own data property. | 
| ECMAScript Latest Draft (ECMA-262) The definition of 'RegExp.prototype.ignoreCase' in that specification. | Draft | 
Browser compatibility
| Feature | Chrome | Edge | Firefox (Gecko) | Internet Explorer | Opera | Safari | 
|---|---|---|---|---|---|---|
| Basic support | (Yes) | (Yes) | (Yes) | (Yes) | (Yes) | (Yes) | 
| Prototype accessor property | ? | ? | 38 (38) | ? | ? | ? | 
| Feature | Android | Chrome for Android | Edge | Firefox Mobile (Gecko) | IE Mobile | Opera Mobile | Safari Mobile | 
|---|---|---|---|---|---|---|---|
| Basic support | (Yes) | (Yes) | (Yes) | (Yes) | (Yes) | (Yes) | (Yes) | 
| Prototype accessor property | ? | ? | ? | 38.0 (38) | ? | ? | ? |