如何新建一个有重复元素的数组

Question

类似['a','b','c','d','e','a','b','c','a','b','c','a','b','c']这样的 有没有高级点的写法

Answer 1

function getArr($count)

{

$str = 'abc';

$arr = array();

for($i=0;$i<$count;$i++)

{

    $rand = rand(0,2);

    $arr[] = $str[$rand];

}

}

$count为你想要新建的数组的个数，主要利用能通过下标获取字符串的某个字符

Answer 2

function repeatArr(arr, len, start) {

  var ret = [];

  for (var i = start || 0; i < len; i++) {

    ret.push(arr[i%arr.length]);

  }

  return ret;

}

repeatArr('abcde'.split(''), 10);

//["a", "b", "c", "d", "e", "a", "b", "c", "d", "e", "a", "b", "c", "d"]

function repeatArr(arr, repeats) {

  var ret = [];

  for (var i = 0; i < repeats.length; i++) {

    for (var j = repeats[i][0]; j < repeats[i][1]; j++) {

      ret.push(arr[j % arr.length]);

    }

  }

  return ret;

}

repeatArr('abcde'.split(''), [[0, 5], [0, 3], [0, 3]]);

//["a", "b", "c", "d", "e", "a", "b", "c", "a", "b", "c"]

Answer 3

Array( 10000 ).fill( 0 ).map( o => String.fromCharCode( Math.floor( Math.random() * 26 ) + 97 ) )