Check whether an array exists in an array of arrays?

You can use this

 var a = [ [1,2] , [3,4] ];
 var b = [1,2];
 a = JSON.stringify(a);
 b = JSON.stringify(b);

then you can do just an indexOf() to check if it is present

var c = a.indexOf(b);
if(c != -1){
    console.log('element present');
}