检查一个元素是否存在于对象数组中

Question

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.

Answer 1

Use array.some()

 var memberships = [{ id: 1, type: 'guest' }, { id: 2, type: 'member' } ]; var status = memberships.some(function(el) { return (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.

Answer 2

You can use Array#some method:

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

Then, if(memberExists) ...

Answer 3

You can use Array#some

 var memberships = [ { id: 1, type: 'guest' }, { id: 2, type: 'member' } ]; console.log(memberships.some(m=>m.type==='member'));

Answer 4

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
}

Answer 5

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

Answer 6

    var memberships = [
        {
            "Name": "family_name",
            "Value": "Krishna"
        },
        {
            "Name": "email",
            "Value": "harikrishnar88@gmail.com"
        }
    ];

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