Array.prototype.map()

Defination
The map() method creates a new array with the results of calling a provided function on every element in the calling array.
Syntax
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var new_array = arr.map(function callback(currentValue, index, array) {
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    // Return element for new_array
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}[, thisArg])
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Examples
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var numbers = [1, 5, 10, 15];
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var doubles = numbers.map(function(x) {
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   return x * 2;
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});
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// doubles is now [2, 10, 20, 30]
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// numbers is still [1, 5, 10, 15]
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​
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var numbers = [1, 4, 9];
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var roots = numbers.map(Math.sqrt);
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// roots is now [1, 2, 3]
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// numbers is still [1, 4, 9]
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Usage
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const numbers = [1, 2, 3, 4, 5];
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const listItems = numbers.map((number) =>
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  <li>{number}</li>
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);
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References
​MDN Array.prototype.map()​

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