javascript - JavaScript是否具有类似“ range（）”的方法来在提供的范围内生成范围？(Does JavaScript have a method like “range()” to generate a range within the supplied bounds?)

Question

In PHP, you can do...

(在PHP中，您可以...)

range(1, 3); // Array(1, 2, 3)
range("A", "C"); // Array("A", "B", "C")

That is, there is a function that lets you get a range of numbers or characters by passing the upper and lower bounds.

(也就是说，有一个函数可以让您通过传递上下限来获得一定范围的数字或字符。)

Is there anything built-in to JavaScript natively for this?

(为此，JavaScript是否内置任何内置功能？)

If not, how would I implement it?

(如果没有，我将如何实施？)

  ask by alex translate from so

Answer 1

Numbers

(号码)

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

Character iteration

(角色迭代)

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

Iteration

(迭代)

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"

As functions

(作为功??能)

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

(作为键入函数)

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)))
}

lodash.js _.range() function

(lodash.js _.range()函数)

_.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]
_.range(0, 30, 5);
 => [0, 5, 10, 15, 20, 25]
_.range(0, -10, -1);
 => [0, -1, -2, -3, -4, -5, -6, -7, -8, -9]
String.fromCharCode(..._.range('A'.charCodeAt(0), 'D'.charCodeAt(0) + 1));
 => "ABCD"

Old non es6 browsers without a library:

(没有库的旧的非es6浏览器：)

Array.apply(null, Array(5)).map(function (_, i) {return i;});
 => [0, 1, 2, 3, 4]

 console.log([...Array(5).keys()]); 

Thanks.

(谢谢。)

(ES6 credit to nils petersohn and other commenters)

(（ES6归功于nils petersohn和其他评论者）)