How to check if a value exists in an object using JavaScript

Question

I have an object in JavaScript:

var obj = {
   "a": "test1",
   "b": "test2"
}

How do I check that te

Answer 1

Try:

var obj = {
   "a": "test1",
   "b": "test2"
};

Object.keys(obj).forEach(function(key) {
  if (obj[key] == 'test1') {
    alert('exists');
  }
});

Or

var obj = {
   "a": "test1",
   "b": "test2"
};

var found = Object.keys(obj).filter(function(key) {
  return obj[key] === 'test1';
});

if (found.length) {
   alert('exists');
}

This will not work for NaN and -0 for those values. You can use (instead of ===) what is new in ECMAScript 6:

 Object.is(obj[key], value);

With modern browsers you can also use:

var obj = {
   "a": "test1",
   "b": "test2"
};

if (Object.values(obj).includes('test1')) {
  alert('exists');
}