Javascript 2d array indexOf

Question

I have a 2d array like this:

var arr = [[2,3],[5,8],[1,1],[0,9],[5,7]];

Each index stores an inner array containing the coordinates of some

Answer 1

Here is a solution done using prototype so the usage resembles that of indexOf but for 2d arrays. Use in the same way: arr.indexOf2d([2,3]);

var arr = [[2,3],[5,8],[1,1],[0,9],[5,7]];

Array.prototype.indexOf2d = function(item) {
    // arrCoords is an array with previous coordinates converted to strings in format "x|y"
    arrCoords = JSON.stringify(this.map(function(a){return a[0] + "|" + a[1]}));

    // now use indexOf to find item converted to a string in format "x|y"
    return arrCoords.indexOf(item[0] + "|" + item[1]) !== -1;
}

arr.indexOf2d([2,3]); // true
arr.indexOf2d([1,1]); // true
arr.indexOf2d([6,1]); // false