Delete field row column in JavaScript array

var array = [
        {"a":"1","b":"3"},
        {"a":"2","b":"5"}
]
for (i=0; i < array.length; i++) {
    delete array[i].b;
}
return JSON.stringify(array);

With a function:

function unsetKey(obj_array, key) {
    for (i=0; i < obj_array.length; i++) {
        delete obj_array[i][key];
    }
    return obj_array;
}

then it can be called like this:

array = unsetKey(array, 'b')