Question

原始数组是newData。我想为newData添加一个数组元素，添加的数组元素应该有Rank 1。

问题是两个记录的Rank都会更新为1。第二记录的等级应为1，第一记录的等级应为null

请告诉我这里我做错了什么。

let newData = [{
    "key1": {
        "cc":'IND'   
    },          
    "key2": {
        "rank": null
    }
}];

let setData = newData.concat(newData.slice());

setData.forEach(data => { 
    data.key2.rank =+ 1;
});

Answer 1

您可以尝试以下

let newData = [{"key1": {"cc":'IND' }, "key2": {"rank": null}}];

    // Concatenate arrays use spread operator and can use map rather than slice
    let setData = [...newData, ...newData.map(data => { 
        /* Objects are passed by reference, you need to break the reference
         * to create the clone of the object. */
        data = JSON.parse(JSON.stringify(data));
        data.key2.rank =+ 1; 
        return data;
    })];

console.log(setData);

Answer 2

setData.forEach(data => { 
  data.key2.rank += 1;
});

尝试将您的运营商从=+转换为+=而不是

复制数组元素修改并再次添加

2 个答案: