在PHP中,您可以。。。

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

也就是说,有一个函数可以通过传递上下限来获得一系列数字或字符。

JavaScript本机是否有内置的功能?如果没有,我将如何实施?


当前回答

---更新(感谢@lokhmakov简化)---

另一个使用ES6发生器的版本(参见伟大的Paolo Moretti回答ES6发生器):

const RANGE = (x,y) => Array.from((function*(){
  while (x <= y) yield x++;
})());

console.log(RANGE(3,7));  // [ 3, 4, 5, 6, 7 ]

或者,如果我们只需要可迭代,那么:

const RANGE_ITER = (x,y) => (function*(){
  while (x <= y) yield x++;
})();

for (let n of RANGE_ITER(3,7)){
  console.log(n);
}

// 3
// 4
// 5
// 6
// 7

---原始代码为:---

const RANGE = (a,b) => Array.from((function*(x,y){
  while (x <= y) yield x++;
})(a,b));

and

const RANGE_ITER = (a,b) => (function*(x,y){
  while (x <= y) yield x++;
})(a,b);

其他回答

/**
 * @param {!number|[!number,!number]} sizeOrRange Can be the `size` of the range (1st signature) or a
 *   `[from, to]`-shape array (2nd signature) that represents a pair of the *starting point (inclusive)* and the
 *   *ending point (exclusive)* of the range (*mathematically, a left-closed/right-open interval: `[from, to)`*).
 * @param {!number} [fromOrStep] 1st signature: `[from=0]`. 2nd signature: `[step=1]`
 * @param {!number} [stepOrNothing] 1st signature: `[step=1]`. 2nd signature: NOT-BEING-USED
 * @example
 * range(5) ==> [0, 1, 2, 3, 4] // size: 5
 * range(4, 5)    ==> [5, 6, 7, 8]  // size: 4, starting from: 5
 * range(4, 5, 2) ==> [5, 7, 9, 11] // size: 4, starting from: 5, step: 2
 * range([2, 5]) ==> [2, 3, 4] // [2, 5) // from: 2 (inclusive), to: 5 (exclusive)
 * range([1, 6], 2) ==> [1, 3, 5] // from: 1, to: 6, step: 2
 * range([1, 7], 2) ==> [1, 3, 5] // from: 1, to: 7 (exclusive), step: 2
 * @see {@link https://stackoverflow.com/a/72388871/5318303}
 */
export function range (sizeOrRange, fromOrStep, stepOrNothing) {
  let from, to, step, size
  if (sizeOrRange instanceof Array) { // 2nd signature: `range([from, to], step)`
    [from, to] = sizeOrRange
    step = fromOrStep ?? 1
    size = Math.ceil((to - from) / step)
  } else { // 1st signature: `range(size, from, step)`
    size = sizeOrRange
    from = fromOrStep ?? 0
    step = stepOrNothing ?? 1
  }
  return Array.from({length: size}, (_, i) => from + i * step)
}

示例:

控制台日志(范围(5),//[0,1,2,3,4]//size:5范围([2,5]),//[2,3,4]//[2、5)//从:2(含)到:5(不含)范围(4,2),//[2,3,4,5]//大小:4,从:2开始范围([1,6],2),//[1,3,5]//从:1到:6,步骤:2范围([1,7],2),//[1,3,5]//从:1到:7(不含),步骤:2)<脚本>函数范围(sizeOrRange、fromOrStep、stepOrNothing){让从、到、步长、大小if(sizeOrRange instanceof Array){//第二个签名:`range([from,to],step)`[from,to]=sizeOrRange步骤=来自或步骤??1.size=数学ceil((to-from)/步长)}else{//第一个签名:`range(大小,从,步)`size=sizeOrRangefrom=来自或步骤??0step=stepOrNothing??1.}return Array.from({length:size},(_,i)=>from+i*step)}</script>

…更大范围,使用生成器功能。

function range(s, e, str){
  // create generator that handles numbers & strings.
  function *gen(s, e, str){
    while(s <= e){
      yield (!str) ? s : str[s]
      s++
    }
  }
  if (typeof s === 'string' && !str)
    str = 'abcdefghijklmnopqrstuvwxyz'
  const from = (!str) ? s : str.indexOf(s)
  const to = (!str) ? e : str.indexOf(e)
  // use the generator and return.
  return [...gen(from, to, str)]
}

// usage ...
console.log(range('l', 'w'))
//=> [ 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w' ]

console.log(range(7, 12))
//=> [ 7, 8, 9, 10, 11, 12 ]

// first 'o' to first 't' of passed in string.
console.log(range('o', 't', "ssshhhooooouuut!!!!"))
// => [ 'o', 'o', 'o', 'o', 'o', 'u', 'u', 'u', 't' ]

// only lowercase args allowed here, but ...
console.log(range('m', 'v').map(v=>v.toUpperCase()))
//=> [ 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V' ]

// => and decreasing range ...
console.log(range('m', 'v').map(v=>v.toUpperCase()).reverse())

// => ... and with a step
console.log(range('m', 'v')
          .map(v=>v.toUpperCase())
          .reverse()
          .reduce((acc, c, i) => (i % 2) ? acc.concat(c) : acc, []))

// ... etc, etc.

希望这有用。

我的代码高尔夫同事想出了这个(ES6),包容的:

(s,f)=>[...Array(f-s+1)].map((e,i)=>i+s)

非包容性:

(s,f)=>[...Array(f-s)].map((e,i)=>i+s)

您可以创建自己的es6系列版本

常量范围=(最小值,最大值)=>{const arr=数组(最大-最小+1).fill(0).map((_,i)=>i+min);返回arr;}控制台日志(范围(0,5));console.log(范围(2,8))

下面是实现自己的可迭代范围函数的方法。

//实施范围功能范围(开始、结束){返回{从:开始,结束,[Symbol.iiterator](){this.current=this.from;返回此;},next(){if(this.current<=this.to){返回{done:false,值:this.current++};}其他{返回{done:true};}}};}//迭代每个值for(设范围数(1,5)){console.log(num);//1, 2, 3, 4, 5}