Quickly find an element in an array and return the subscript example_javascript skills

Copy code The code is as follows:

//General implementation one:
function isHasElementOne(arr,value ){
for(var i = 0,vlen = arr.length; i < vlen; i ){
if(arr[i] == value){
return i;
}
}
return -1;
}
//Implementation 2:
function isHasElementTwo(arr,value){
var str = arr.toString();
var index = str.indexOf(value);
if(index >= 0){
//There is a return index
var reg1 = new RegExp("((^|,)" value "(, |$))","gi");
return str.replace(reg1,"$2@$3").replace(/[^,@]/g,"").indexOf("@");
}else{
return -1;//This item does not exist
}
}

Supplementary:

Copy code The code is as follows:

function isHasElement(arr,value){
var str = arr.toString();
var index = str.indexOf(value);
if(index >= 0){
//Return index exists
//"(^" value ",)|(," value ",) |(," value "$)"
value = value.toString().replace(/([|])/g,"\$1");
var reg1 = new RegExp("((^ |,)" value "(,|$))","gi");
return str.replace(reg1,"$2@$3").replace(/[^,@]/g,"") .indexOf("@");
}else{
return -1;//This item does not exist
}
}

Recently writing jquery combobox I encountered efficiency issues when plugging in, and coupled with the class selection of the jquery selector, the efficiency was very slow. After adopting the second method, the efficiency is obviously improved.