Copy code The code is as follows: <br>//From a given array arr, randomly return num unique items<br>function getArrayItems(arr, num) {<br> //Create a new array and copy the incoming array for operation , instead of directly operating the incoming array;<br> var temp_array = new Array();<br> for (var index in arr) {<br> temp_array.push(arr[index]);<br> }<br> //The taken out numerical items are stored in this array <br> var return_array = new Array();<br> for (var i = 0; i<num; i) {<BR> //Judge if the array is still There are elements that can be taken out in case the subscript goes out of bounds <BR> if (temp_array.length>0) {<br> //Generate a random index in the array <br> var arrIndex = Math.floor(Math.random() ( At this time, temp_array becomes a new array <br> temp_array.splice(arrIndex, 1); Requires 20 items. <re> Break; <br>} <br>} <br> Return Return_array; <br>} <br> <br>//Test<br>var ArrList=[1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19 ,20,21,22,23,24,25,26,27,28,29,30,31,32,33];<br>alert(getArrayItems(ArrList,6));<br></script> ;<br><p></p></re> </div>
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