check object value in array of obcts code example

Example 1: check if object is present in array javascript

//Use something like this:

function containsObject(obj, list) {
    var i;
    for (i = 0; i < list.length; i++) {
        if (list[i] === obj) {
            return true;
        }
    }

    return false;
}

//In this case, containsObject(car4, carBrands) is true. Remove the carBrands.push(car4); call and it will return false instead. If you later expand to using objects to store these other car objects instead of using arrays, you could use something like this instead:

function containsObject(obj, list) {
    var x;
    for (x in list) {
        if (list.hasOwnProperty(x) && list[x] === obj) {
            return true;
        }
    }

    return false;
}

Example 2: react array if id is present do not add element

addPerson = (person) => {
    let filteredPerson = this.state.likes.filter(like => like.name !== person.name);
    this.setState({
      likes: [...filteredPerson, person]
    })        
  }