The label statement in JavaScript, and the application

Label statement: You can add tags to your code for future use.

Syntax: label:statement

Example:

Start:    for (var i=0;i<10;i++) {    console.log (i);  };

Example extensions:

Start:    for (var i=0;i<10;i++) {    console.log (i);      for (var j=0;j<5;j++) {      console.log (' J ' +j);       if (i>5) {        // break ;      Only the last loop is terminated, and the last loop does not terminate the break         start;      // all terminated.       }    }  };

Application Scenarios:

varItemsid = [1,3];varall = [[{Id:1,name:hehe},{id:3,name:hehe}],[{id:2,name:hehe},{id:4, Name:hehe}]];//we have the top two arrays, ITEMSID is the ID array, all is a two-dimensional array, where the elements are, according to the parity of the ID placed, the object of the item. Now we want to find the object corresponding to the ID in each items, this time we need multiple loops to find: for(vari=0;i<itemsid.length;i++){     for(varj=0;j<all.length;j++){         for(vark=0;k<all[j].length;k++){            if(All[j][k].id = =Itemsid[i])                {Console.log (all[j][k]);  Break; }        }    }}//At this point we will find that when we find the right object, using break can only jump out of the inner K Loop, and the J Loop will go on. There are a lot of unnecessary loops. We hope that, when found, jump directly outside the J Loop and start looking for the next ID. At this point, we need to use the label. The code is as follows: for(vari=0;i<itemsid.length;i++) {outpoint: for(varj=0;j<all.length;j++){         for(vark=0;k<all[j].length;k++){            if(All[j][k].id = =Itemsid[i])                {Console.log (all[j][k]);  BreakOutpoint; }        }    }}//in this way, when all[j][k].id = = Itemsid[i], you will jump out of the outpoint position, jump out of two loops, starting from the next ID to find. Many times less cycles. 

The label statement in JavaScript, and the application