JS to determine whether there is a value in the object in the array

1.some() Method

Return... If conditions are met true, Otherwise return to false.

var arr = [{
    name: " Zhang San ",
    age: "20"
}, {
    name: " Li Si ",
    age: "21"
}]
var res = arr.some(function(item) {
    if (item.name == " Li Si ") {
        return true;
    }
})
console.log(res); //  return true

2.find() Method

Return the current object if the condition is met , Otherwise return to undefined.

var arr = [{
    name: " Zhang San ",
    age: "20"
}, {
    name: " Li Si ",
    age: "21"
}]
var res = arr.find((v) => {
    return v.age=== '20';
});
console.log(res); //  return  {name: " Zhang San ",age: "20"}

3.findIndex() Method

The index value of the element that meets the condition , Otherwise return to -1.

var arr = [{
    name: " Zhang San ",
    age: "20"
}, {
    name: " Little Luban ",
    age: "21"
}]
var res = arr.findIndex((v) => {
    return v.age=== '20';
});
console.log(res); //  return 0