JS判斷一個數組中是否有重複值的三種方法

方法一: var s = ary.join(",")+","; for(var i=0;i<ary.length;i++) { if(s.replace(ary[i]+",","").indexOf(ary[i]+",")>-1) { alert("數組中有重複元素：" + ary[i]); break; } } 方法二: var ary = new Array("111","22","33","111"); var nary=ary.sort(); for(var i=0;i<ary.length;i++){ if (nary[i]==nary[i+1]){ alert("數組重複內容："+nary[i]); } } 方法三: function isRepeat(arr){ var hash = {}; for(var i in arr) { if(hash[arr[i]]) return true; hash[arr[i]] = true; } return false; }