How Can I Create a Range Function in JavaScript Similar to PHP's range()?

Does JavaScript Have a Range Function Like PHP's range()?

PHP's range() function allows you to effortlessly generate an array of numbers or characters within specified bounds. However, JavaScript does not have a built-in function for this purpose. Here are a few methods to implement this functionality in JavaScript:

Numbers

Utilize the Array.keys() method:

[...Array(5).keys()]; // [0, 1, 2, 3, 4]

Character Iteration

Leverage String.fromCharCode() to iterate through character ranges:

String.fromCharCode(...[...Array('D'.charCodeAt(0) - 'A'.charCodeAt(0) + 1).keys()].map(i => i + 'A'.charCodeAt(0)));
// "ABCD"

Generic Iteration

Employ for...of loops in conjunction with String.fromCharCode():

for (const x of Array(5).keys()) {
  console.log(x, String.fromCharCode('A'.charCodeAt(0) + x));
}
// 0,"A" 1,"B" 2,"C" 3,"D" 4,"E"

Custom Range Functions

Create reusable functions to generate ranges:

function range(size, startAt = 0) {
    return [...Array(size).keys()].map(i => i + startAt);
}

function characterRange(startChar, endChar) {
    return String.fromCharCode(...range(endChar.charCodeAt(0) -
            startChar.charCodeAt(0), startChar.charCodeAt(0)))
}

As Typed Functions

TypeScript users can define typed functions:

function range(size:number, startAt:number = 0):ReadonlyArray<number> {
    return [...Array(size).keys()].map(i => i + startAt);
}

function characterRange(startChar:string, endChar:string):ReadonlyArray<string> {
    return String.fromCharCode(...range(endChar.charCodeAt(0) -
            startChar.charCodeAt(0), startChar.charCodeAt(0)))
}

External Libraries

Alternatively, you can utilize third-party libraries such as lodash.js, which provides a range() function:

_.range(10); // [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
_.range(1, 11); // [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]

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