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W3Schools
w3schools.com › js › js_number_methods.asp
JavaScript Number Methods
In JavaScript, a number can be a primitive value (typeof = number) or an object (typeof = object). The valueOf() method is used internally in JavaScript to convert Number objects to primitive values.
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MDN Web Docs
developer.mozilla.org › en-US › docs › Web › JavaScript › Reference › Global_Objects › Array
Array - JavaScript | MDN
You can call array methods on them even if they don't have these methods themselves. ... Creates a new Array object. ... Returns the Array constructor. ... Creates a new Array instance from an iterable or array-like object. ... Creates a new Array instance from an async iterable, iterable, or array-like object. ... Returns true if the argument is an array, or false otherwise. ... Creates a new Array instance with a variable number of arguments, regardless of number or type of the arguments.
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Programiz
programiz.com › javascript › numbers
JavaScript Number (with Examples)
Here is a list of built-in number methods in JavaScript.
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GeeksforGeeks
geeksforgeeks.org › javascript › javascript-numbers
JavaScript Numbers - GeeksforGeeks
Some operations such as those which work with an array, string indexes, or date/time expect integers. After performing the coercion if the number is greater than 0 it is returned as the same and if the number NaN or -0, it is returned as 0. The result is always an integer. In Javascript, there ...
Published   July 11, 2025
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DEV Community
dev.to › catherineisonline › 12-javascript-number-methods-cheatsheet-1oie
12 JavaScript Number Methods Cheatsheet - DEV Community
May 15, 2025 - And just like in strings, the number also has a method to retrieve the primitive value from the number object. This is usually done automatically. Congratulations! If you finally reached this part and read about all number methods, I hope they are much easier to understand now and you will be able to use them to manipulate the data! ... #javascript #webdev #datatypes How to Find the Symmetric Difference Between Two Arrays in JavaScript
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JavaScript.info
javascript.info › tutorial › the javascript language › data types
Array methods
Now it works as intended. Let’s step aside and think about what’s happening. The arr can be an array of anything, right? It may contain numbers or strings or objects or whatever. We have a set of some items. To sort it, we need an ordering function that knows how to compare its elements. The default is a string order. The arr.sort(fn) method implements a generic sorting algorithm.
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W3Schools
w3schools.com › jsref › jsref_number.asp
JavaScript Number() Method
It is supported in all browsers: Convert different numbers to a number: Number(999); Number("999"); Number("999 888"); Try it Yourself » · Convert different arrays to a number: Number([9]); Number([9.9]); Number([9,9]); Try it Yourself » · ❮ Previous JavaScript Global Methods Next ❯ ·
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W3Schools
w3schoolsua.github.io › js › js_number_methods_en.html
JavaScript Number Methods. Lessons for beginners. W3Schools in English
But with JavaScript, methods and properties are also available to primitive values, because JavaScript treats primitive values as objects when executing methods and properties. The toString() method returns a number as a string.
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GeeksforGeeks
geeksforgeeks.org › javascript › javascript-array-methods
JavaScript Array Methods - GeeksforGeeks
To help you perform common tasks ... find, and transform array elements with ease. ... The length property of an array returns the number of elements in the array....
Published   August 5, 2025
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GeeksforGeeks
geeksforgeeks.org › javascript-number-reference
JavaScript Number Reference | GeeksforGeeks
May 26, 2023 - They come with a wide range of built-in methods that allow developers to manipulate, transform, and interact with array elements.Some of the most important array methods in JavaScript areTable of Content1. JavaScript push() Metho ... JavaScript Array is used to store multiple elements in a single variable. It can hold various data types, including numbers, strings, objects, and even other arrays.
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MDN Web Docs
developer.mozilla.org › en-US › docs › Web › JavaScript › Reference › Global_Objects › Number
Number - JavaScript | MDN
The Number constructor contains constants and methods for working with numbers. Values of other types can be converted to numbers using the Number() function. Numbers are most commonly expressed in literal forms like 255 or 3.14159.
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Mozilla
developer.mozilla.org › en-US › docs › Web › JavaScript › Guide › Data_structures
JavaScript data types and data structures - JavaScript | MDN
All primitive types, except null and undefined, have their corresponding object wrapper types, which provide useful methods for working with the primitive values. For example, the Number object provides methods like toExponential(). When a property is accessed on a primitive value, JavaScript automatically wraps the value into the corresponding wrapper object and accesses the property on the object instead.
Top answer
1 of 16
3976

In ES6 using Array from() and keys() methods.

Array.from(Array(10).keys())
//=> [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]

Shorter version using spread operator.

[...Array(10).keys()]
//=> [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]

Start from 1 by passing map function to Array from(), with an object with a length property:

Array.from({length: 10}, (_, i) => i + 1)
//=> [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
2 of 16
901

You can do so:

var N = 10; 
Array.apply(null, {length: N}).map(Number.call, Number)

result: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]

or with random values:

Array.apply(null, {length: N}).map(Function.call, Math.random)

result: [0.7082694901619107, 0.9572225909214467, 0.8586748542729765, 0.8653848143294454, 0.008339877473190427, 0.9911756622605026, 0.8133423360995948, 0.8377588465809822, 0.5577575915958732, 0.16363654541783035]

Explanation

First, note that Number.call(undefined, N) is equivalent to Number(N), which just returns N. We'll use that fact later.

Array.apply(null, [undefined, undefined, undefined]) is equivalent to Array(undefined, undefined, undefined), which produces a three-element array and assigns undefined to each element.

How can you generalize that to N elements? Consider how Array() works, which goes something like this:

function Array() {
    if ( arguments.length == 1 &&
         'number' === typeof arguments[0] &&
         arguments[0] >= 0 && arguments &&
         arguments[0] < 1 << 32 ) {
        return [ … ];  // array of length arguments[0], generated by native code
    }
    var a = [];
    for (var i = 0; i < arguments.length; i++) {
        a.push(arguments[i]);
    }
    return a;
}

Since ECMAScript 5, Function.prototype.apply(thisArg, argsArray) also accepts a duck-typed array-like object as its second parameter. If we invoke Array.apply(null, { length: N }), then it will execute

function Array() {
    var a = [];
    for (var i = 0; i < /* arguments.length = */ N; i++) {
        a.push(/* arguments[i] = */ undefined);
    }
    return a;
}

Now we have an N-element array, with each element set to undefined. When we call .map(callback, thisArg) on it, each element will be set to the result of callback.call(thisArg, element, index, array). Therefore, [undefined, undefined, …, undefined].map(Number.call, Number) would map each element to (Number.call).call(Number, undefined, index, array), which is the same as Number.call(undefined, index, array), which, as we observed earlier, evaluates to index. That completes the array whose elements are the same as their index.

Why go through the trouble of Array.apply(null, {length: N}) instead of just Array(N)? After all, both expressions would result an an N-element array of undefined elements. The difference is that in the former expression, each element is explicitly set to undefined, whereas in the latter, each element was never set. According to the documentation of .map():

callback is invoked only for indexes of the array which have assigned values; it is not invoked for indexes which have been deleted or which have never been assigned values.

Therefore, Array(N) is insufficient; Array(N).map(Number.call, Number) would result in an uninitialized array of length N.

Compatibility

Since this technique relies on behaviour of Function.prototype.apply() specified in ECMAScript 5, it will not work in pre-ECMAScript 5 browsers such as Chrome 14 and Internet Explorer 9.

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CoderPad
coderpad.io › blog › development › javascript-array-methods
A Thorough Guide To JavaScript Array Methods with Examples - CoderPad
June 7, 2023 - Handling all this from scratch can be very complex, but JavaScript already has some built-in methods you can use to perform all these tasks efficiently. Here is an overview of the most common methods for iterating over your arrays.
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Medium
medium.com › @aayushgiri1234 › javascript-number-methods-a-comprehensive-guide-28a0c1c68588
JavaScript Number Methods: A Comprehensive Guide | by Aayush Giri | Medium
June 22, 2023 - In JavaScript, a number can be a primitive value (typeof = number) or an object (typeof = object). There is no reason to use the valueOf() method in your code, as JavaScript automatically converts Number objects to primitive values when necessary.
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freeCodeCamp
freecodecamp.org › news › javascript-range-create-an-array-of-numbers-with-the-from-method
JavaScript Range – How to Create an Array of Numbers with .from() in JS ES6
November 7, 2024 - The .from() method is a static method of the Array object in JavaScript ES6. It creates a new, shallow-copied Array instance from an array-like or iterable object like map and set.
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TutorialsPoint
tutorialspoint.com › home › javascript › javascript number object
JavaScript Number Object
September 1, 2008 - In the place of number, if you provide any non-number argument, then the argument cannot be converted into a number, it returns NaN (Not-a-Number). We can also create the number primitives by assigning the numeric values to the variables − ... The JavaScript automatically converts the number primitive to the Number objects. So we can use all properties and methods of Number object on number primitives.
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CodeWithHarry
codewithharry.com › tutorial › js-array-and-array-methods
Arrays and Array Methods | JavaScript Tutorial | CodeWithHarry
Some of the most commonly used array methods are: length - This method returns the number of elements in an array.
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Launch School
launchschool.com › books › javascript › read › arrays
Understand JavaScript Arrays and Common Array Methods with Clarity
> let numbers = [1, 2, 3, 4] > let reversedNumbers = numbers.slice().reverse(); > reversedNumbers = [ 4, 3, 2, 1 ] > numbers = [ 1, 2, 3, 4 ] Arrays are a valuable data structure. You'll see them all the time in real-world programs; nearly every useful program uses arrays at some point. JavaScript's array type has plenty of built-in methods that can perform the basic operations that programmers need every day.