JavaScript Iterator map()
Example
Return a new array with the square root of all element values:
// Create an iterator
const myIterator = Iterator.from("123456789");
// Map the Iterator
const mappedIterator = myIterator.map(x => x * 2);
Try it Yourself »
Description
map() creates a new iterator from calling a 
function for every iterator element.
map() does not execute the function for empty elements.
map() does not change the original iterator.
Syntax
iterator.map(function(currentValue, index, arr), thisValue)
Parameters
| Parameter | Description | 
| function() | Required. A function to be run for each iterator element.  | 
  
| currentValue | Required. The value of the current element.  | 
  
| index | Optional. The index of the current element.  | 
  
| arr | Optional. The array of the current element.  | 
  
| thisValue | Optional. Default value undefined.A value passed to the function to be used as its this value. | 
  
Return Value
| Type | Description | 
| An iterator | The results of running a function for each iterator element. | 
Browser Support
iterator.map() is a JavaScript 2025 feature.
ES 2025 is fully supported in all modern browsers since May 2025:
| Chrome 136  | 
    Edge 136  | 
    Firefox 129  | 
    Safari 18.2  | 
    Opera 120  | 
  
| Apr 2025 | Apr 2025 | Aug 2024 | Des 2024 | May 2025 |