Javascript to determine whether there are duplicates in the array is worth three practical methods _ javascript tips-JS tutorial

There are many methods to determine whether there are repeated values in the array. This article recommends three practical methods for you. If you are interested, refer to the following. I hope to help you with Method 1:

The Code is as follows:

Var ary = new Array ("111", "22", "33", "111 ");

Var s = ary. join (",") + ",";

For (var I = 0; I
If (s. replace (ary [I] + ",", ""). indexOf (ary [I] + ",")>-1 ){

Alert ("repeated elements in the array:" + ary [I]);

Break; Foreign Language House

}

}

Method 2:

The Code is as follows:

Var ary = new Array ("111", "22", "33", "111 ");

Var nary = ary. sort ();

For (var I = 0; I
If (nary [I] = nary [I + 1]) {

Alert ("repeated array content:" + nary [I]);

}

}

Method 3: Inland Transportation

The Code is as follows:

Function isRepeat (arr ){

Var hash = {};

For (var I in arr ){

If (hash [arr [I])

Return true;

Hash [arr [I] = true;

}

Return false;

}