如何基于另一个数组中的键/值对为一个数组中的对象分配属性值？

Question

I have an array that looks like this:

var fields = [{Name: 'FirstName', Value: '', Display: 'First Name'}, {...}]

I have another array that looks like this:

var nameValue = [{'FirstName':'John'}, {'LastName':'Doe'}, ...]

How do I assign the Value property for each field in the first array using the name/value pairs in the second array?

Desired result:

fields = [{Name: 'FirstName', Value: 'John', Display: 'First Name'}, {...}]

Answer 1

You could create an object first with all needed values and iterate fields , make a check if a property with the name exists and then assign the value.

 var fields = [{ Name: 'FirstName', Value: '', Display: 'First Name' }], nameValue = [{ FirstName: 'John' }, { LastName: 'Doe' }], values = Object.assign({}, ...nameValue); fields.forEach(o => (o.Name in values) && (o.Value = values[o.Name])); console.log(fields); 

Answer 2

Loop, check, assign:

fields.forEach(function(field) {
    let key = field.Name;
    for (let i = 0; i < nameValue.length; i++) {
        for (let nameKey in nameValue[i]) {
            if (nameKey == key) {
                field.Value = nameValue[i][key]
                break;
            }
        }
    }
});

Answer 3

First combine all the names and values into a single object:

var nvObject = {};
nameValue.forEach(function (e) {
    for (key in e) {
        nvObject[key] = e[key];
    }
});

Now nvObject = { FirstName: 'John', LastName: 'Doe', ... } . Perhaps you could construct nameValue like this in the first place, instead of making it an array of objects.

Then you can use this to update the other array.

$fields.forEach(function (e) {
    if (e.Name in nvObject) {
        e.Value = nvObject[e.Name];
    }
});