数组推送行为

Question

虽然我有一些基本的JavaScript背景,但我偶然发现了我写的这段代码:

var data=[{"_id":"57b3e7ec9b209674f1459f36","fName":"Tom","lName":"Moody","email":"Tom@example.com","age":30},{"_id":"57b3e8079b209674f1459f37","fName":"Pat","lName":"Smith","email":"pat@example.com","age":32},{"_id":"57b3e8209b209674f1459f38","fName":"Sam","lName":"Dawn","email":"sam@example.com","age":28},{"_id":"57b3e8219b209674f1459f39","fName":"Sam","lName":"Dawn","email":"sam@example.com","age":28}]
var tempArr=[];
var table=[];
var dataArr = Object.keys(data).map(function(k) { return data[k] });
dataArr.forEach(function(user) {
  tempArr[0]=user.fName;
  tempArr[1]=user.lName;
  tempArr[2]=user.email;
  tempArr[3]=user.age;
  table.push(tempArr);
  console.log('table'+JSON.stringify(table));
 });

在最后一个循环中,我希望表包含Tom,Pat和Sam的数组.相反,这就是我得到的:

table[["Tom","Moody","Tom@example.com",30]]
table[["Pat","Smith","pat@example.com",32],["Pat","Smith","pat@example.com",32]]
table[["Sam","Dawn","sam@example.com",28],["Sam","Dawn","sam@example.com",28],["Sam","Dawn","sam@example.com",28]]
table[["Sam","Dawn","sam@example.com",28],["Sam","Dawn","sam@example.com",28],["Sam","Dawn","sam@example.com",28],["Sam","Dawn","sam@example.com",28]]

为什么push()替换表中的前一个条目？任何帮助将受到高度赞赏.

Answer 1

其他人已经在你的代码中指出了问题.

但是,你也会使事情变得更加复杂.你可以这样做:

var data=[{"_id":"57b3e7ec9b209674f1459f36","fName":"Tom","lName":"Moody","email":"Tom@example.com","age":30},{"_id":"57b3e8079b209674f1459f37","fName":"Pat","lName":"Smith","email":"pat@example.com","age":32},{"_id":"57b3e8209b209674f1459f38","fName":"Sam","lName":"Dawn","email":"sam@example.com","age":28},{"_id":"57b3e8219b209674f1459f39","fName":"Sam","lName":"Dawn","email":"sam@example.com","age":28}];

var table = data.map(function(user) {
    return [
      user.fName,
      user.lName,
      user.email,
      user.age,
    ];
});
      
console.log(table);

或者如果你使用ES6:

var table = data.map(user => [ user.fName, user.lName, user.email, user.age ];