javascript怎么实现range函数

Question

js怎么实现类似python的range函数

Answer 1

一个我经常使用的，而且最短的方式：

[...Array(5).keys()]

Answer 2

let range = (start, end) => new Array(end - start).fill(start).map((el, i) => start + i);

Answer 3

1.Array.from

Array.from(Array(end-start),(el,i)=>start+i)

2.Array.fill.map

Array(end - start).fill(start).map((el, i) => start + i)

3.[...Array.keys()].map

[...Array(end-start).keys()].map((el, i) => start + i)

Answer 4

function range(start,end){
  var arr = [];
  for(var i = start;i < end;i++){
    arr.push(i);
  }
  return arr;
}

range(0,5);

Answer 5

以上面这种遍历数组的思路，lodash库的baseRange.js 提供了最佳方案：

https://github.com/lodash/lod...

Answer 6

Object.defineProperty(Array.prototype,'range',{
    value:function(start,end){
        this.length = end-start;
        for(var i=0;i<this.length;i++){
            this[i] = start+i;
        }
    },
    enumberable:false
})
var arr = new Array();
console.log(arr.range(0,3));  //[0,1,2]

Answer 7

range = (start,end,step)=>[...function*(){while(start<end)yield start,start+=step}()]