I have the following array of objects:

var memberships = [
  {
    id: 1,
    type: 'guest'
  },
  {
    id: 2,
    type: 'member'
  }
];

How can I verify if such an array has at least one element with type 'member'?

Note that the array can also have no elements.

I have the following array of objects:

var memberships = [
  {
    id: 1,
    type: 'guest'
  },
  {
    id: 2,
    type: 'member'
  }
];

How can I verify if such an array has at least one element with type 'member'?

Note that the array can also have no elements.

• javascript
• arrays
• functional-programming

• Does this answer your question? Check if object value exists within a Javascript array of objects and if not add a new object to array – Yogi Commented Dec 24, 2020 at 10:57

6 Answers 6

Use array.some()

var memberships = [{
    id: 1,
    type: 'guest'
  },
  {
    id: 2,
    type: 'member'
  }
];

var status = memberships.some(function(el) {
  return (el.type === 'member');
});

/*
  // Simplified format using arrow functions
  var status = memberships.some(el => el.type === 'member')
*/
console.log(status);

Array.some()

Array.some() executes the callback function once for each element present in the array until it finds one where callback returns a truthy value. If such an element is found, some() immediately returns true. Otherwise, some() returns false.

You can use Array#some method:

const memberExists = memberships.some(member => member.type === 'member');

Then, if(memberExists) ...

I think this may help

let resultArray=memberships.filter(function(item) {
     return item["type"] === 'member';
});

the result array holds the data of the objects that has type member

You can use Array#some

var memberships = [
  {
    id: 1,
    type: 'guest'
  },
  {
    id: 2,
    type: 'member'
  }
];

console.log(memberships.some(m=>m.type==='member'));

You can also use find, which returns the first object if found else undefined.

let a = memberships.find(o => o.type === 'member');

if (a) {
  ...do something
}

    var memberships = [
        {
            "Name": "family_name",
            "Value": "Krishna"
        },
        {
            "Name": "email",
            "Value": "[email protected]"
        }
    ];

    let resultArray=memberships.filter(function(item) {
      return item["Name"] === 'email';
});