javascript object contains value code example

Example 1: check the properties of an object in javascript

for (var name in object) {  
    if (object.hasOwnProperty(name)) { 
        // do something with name                    
    }  
}

// OR

const hero = {
  name: 'Batman'
};

hero.hasOwnProperty('name');     // => true
hero.hasOwnProperty('realName'); // => false

Example 2: test if property exists javascript

const hero = {
  name: 'Batman'
};

hero.hasOwnProperty('name');     // => true
hero.hasOwnProperty('realName'); // => false

Example 3: js does object contain value

// You can turn the values of an Object into an array.
// Then test that a value is present:

// This assumes, that the Object is not nested
// and the value is an exact match:

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

// Note that an array can only have positive index's; so
// checking for a negative index is a super valid way for getting a
// boolean value as a result for the check.
if (Object.values(obj).indexOf('test1') > -1) {
   console.log('Value exists!');
}

Example 4: object contains property javascript

if (x.hasOwnProperty('y')) {}

//or

if ('y' in x) {}

//or

if (x?.y){}