根据值将一个带有对象的数组中的属性添加到另一个数组

Question

I have two arrays of objects like this:

let test = [
{Course: "", Week: "1", Hours: ""}, 
{Course: "", Week: "2", Hours: ""}, 
{Course: "", Week: "3", Hours: ""}
]

let values = [{Course: "A", Week: "3", Hours: "1"}]

I want to add the property from array "values" to array "test so the result will be:

let test = [
{Course: "", Week: "1", Hours: ""}, 
{Course: "", Week: "2", Hours: ""}, 
{Course: "", Week: "3", Hours: "1"}
]

Is this possible? The reason why I have it like this, is I need to specify all weeks at the start, and the values will be added from the user.

Answer 1

First make an object mapping weeks to objects for fast lookup then just loop through the values array:

const lookup = {};
for (const val of test) {
    lookup[val.week] = val;
}
for (const val of values) {
    const cur = lookup[val.week];
    for (const key in val) {
        if (key === "Hours") {
            cur[key] = (Number(cur[key]) + Number(val[key])).toString();
        } else {
            cur[key] = val[key];
        }
    }
}

Answer 2

Loop through Values - Find the test that matches current value's week and set hours to value's hours

values.forEach((value) => {
    //Find the test that matches current value's week and set hours to value's hours
    test.find(test => test.Week === val.Week).Hours = value.Hours);
});

Answer 3

You can just use array.find function.

 let test = [ {Course: "", Week: "1", Hours: ""}, {Course: "", Week: "2", Hours: ""}, {Course: "", Week: "3", Hours: ""} ] let values = [{Course: "A", Week: "3", Hours: "1"}] var current = test.find((item) => { return item.Week === values[0].Week }) current.Hours += values[0].Hours; console.log(test)