js建立1-100的數組

1. //實現方法一：循環賦值var arr1 = new Array(100);for(var i=0;i<arr1.length;i++){  arr1[i] = i;}console.log(arr1);//實現方法二：push方法實現var arr2 = new Array();for(var i=0;i<100;i++){  arr2.push(i);}console.log(arr2);//實現方法三：whilevar arr3 = new Array();var i = 0;while(i<100){  arr3.push(i);  i++;}console.log(arr3);//實現方法四：do whilevar arr4 = new Array();var i = 0;do{  arr4.push(i);  i++;}while(i<100)console.log(arr4);//實現方法五：var arr5 = Object.keys(Array.apply(null, {length:100})).map(function(item){  return +item;});console.log(arr5);//實現方法六：var arr6 = Array.from({length:100}, (v,k) => k);console.log(arr6);//實現方法七：var arr7 = Array.from(Array(100), (v,k) =>k);console.log(arr7);//實現方法八：var arr8 = new Array(100).keys();console.log(Array.from(arr8));//實現方法九：var arr9 = [];var i = 0;var timer = setInterval(function(){  arr9[i] = i++;  if(i>=100){    clearInterval(timer);    console.log(arr9);  }},1);//實現方法十：var arr = [];var i = 0;function MakeArray(num){  if(i<num){    arr[i] = i++;    MakeArray(num);  }  return arr;}console.log(MakeArray(100));//實現方法十一：var arr11 = new Array(100).toString().split(',').map(function(item,index){  return index;});console.log(arr11);