如何在函數內動態創建javascript對象

Question

我想在每次調用“dataObject”函數時動態創建一個 javascript 對象，所以我想做這樣的事情：

let dataObject = {};

function appendDiv() {
    e = this.event.target;

    //this id changes each time when the function is called
    var current_id = e.id;

    // here I had to initialized it because if I didn't, it would appear an error "TypeError: dataObject[(intermediate value)] is undefined"
    dataObject[`${current_id}`] = {};

    $('#creates').submit(function (event) {
        var i, j;

        for (i = 0; i < nbr_group.value; i++) {
            inputlist = [];

            for (j = 0; j < 3; j++) {
                formChild = document.querySelectorAll('.period-select')[j].value;
                inputlist[j] = formChild;
            }

            dataObject[`${current_id}`][`${i}`] = {
                firstvalue: inputlist[0], 
                secondvalue: inputlist[1], 
                thirdvalue: inputlist[2]    
            }
        }
    });    
}

所以問題是當第一次調用該函數時，子對象將被成功創建，但對該函數的第二次調用會將它們創建為空，例如：

// the first call:
dataObject = {
    '1': {
         '1': { '1': 'some values' }, 
         '2': { '1': 'another value' }
    }
};

//the second call or third or... :
dataObject = {
    '1': {
        '1': { '1': 'some values' }, 
        '2': { '1': 'another value' }
    },
    '2': {}
};        

Answer 1

如果你想復制一個對象，不要使用dataObject[`${current_id}`][`${i}`] = {firstvalue: inputlist[0], secondvalue: inputlist[1], thirdvalue: inputlist[2]}; ，使用這個： let objectCopy = Object.assign({}, dataObject); 其中dataObject是您要復制的對象。