从对象数组迭代对象属性

Question

I have the following array given:

const myArray = [{ id: 1, isSet: true }, { id: 2, isSet: false }, ...];

Actually I want to iterate only the isSet properties of the objects (not all properties). The most simple solution, which came on my mind was the following:

let isSet = false;
for (const obj of myArray) {
    for (const property in obj) {
        if (property === "isSet" && obj.hasOwnProperty(property)) {
            isSet |= obj[property];
        }
    }
}

console.log(isSet);

I think this one does not really look pretty, so has someone a better solution as the given one (maybe also better in runtime)?

Thanks in advance!

Answer 1

You can do this generically if you pass in your set of rules for each property, like so:

 const myArray1 = [{ id: 1, isSet: false }, { id: 2, isSet: false }, { id: 3, isSet: false }]; // check if there is an object with id = 3, isSet = true var conditions = { isSet: (obj) => obj.isSet, id: (obj) => obj.id === 3 }; // check if there is an object with id = 2, isSet = false var conditions2 = { isSet: (obj) => !obj.isSet, id: (obj) => obj.id === 2 }; function testConditions(arr, conditions) { // .some() -- do ANY of the objects match the criteria? return arr.some(obj => { // .every() -- make sure ALL conditions are true for any given object return Object.keys(conditions).every(key => { // run comparitor function for each key for the given object return conditions[key](obj); }); }); } console.log(testConditions(myArray1, conditions)); // false -- no object with id = 3, isSet = true console.log(testConditions(myArray1, conditions2)); // true -- myArray1[1] has id = 2, isSet = false 

Answer 2

You can use the some function of an array.

 const myArray1 = [{ id: 1, isSet: false }, { id: 2, isSet: false }, { id: 3, isSet: false }]; let isSet1 = myArray1.some(obj => obj.isSet === true) console.log(isSet1); const myArray2 = [{ id: 1, isSet: false }, { id: 2, isSet: true }, { id: 3, isSet: false }]; let isSet2 = myArray2.some(obj => obj.isSet === true) console.log(isSet2);