How to find an appropriate object in array by one of its properties

Question

Say, I have that simple array of objects.

var x = [
            {
                id:      1001
                name:    \"Jim\",
                surname: \"         


        

Answer 1

A simple loop will suffice:

for(var i=0, len=x.length; i < len; i++){
    if( x[i].id === 1002){
        //do something with x[i]
    }
}

Even though you are dealing with json remember that it's all just a hierarchy of arrays, objects and primitives.

Answer 2

As of ES2015, JavaScript arrays have find and findIndex methods, both of which are easily polyfilled (see those MDN links for polyfills).

In your case, you'd use find:

var found = x.find(function(entry) { return entry.id == 1002; });

or also using other (non-polyfillable) ES2015 features:

const found = x.find(entry => entry.id == 1002);

Answer 3

The easiest way is to define a find function which takes a predicate

function find(arr, predicate) { 
  for (var i = 0; i < arr.length; i++) {
    if (predicate(arr[i]) {
      return arr[i];
    }
  }
  return null;
}

Then you can just use this method on the array

var found = find(x, function (item) { item.id === 1002 });