从 arrays 中提取 object 元素

Question

我有一个输出如下的数组：

[]
0: {emailAddress: "xxx", squats: "0", steps: "4500", WorkoutDate: "12-5-2020", pullUps: "0", …}
1: {emailAddress: "yyy", squats: "4000", steps: "0", WorkoutDate: "10-5-2020", pullUps: "0", …}
2: {emailAddress: "zzz", WorkoutDate: "05-08-2020"}
length: 3
__proto__: Array(0)

遍历这些项目并提取值的最佳方法是什么？

谢谢您的帮助！

Answer 1

这种情况可能有多种解决方案。 我更喜欢您使用array.map或array.forEach方法循环遍历数组， 使用 for...in方法循环遍历 object 属性。 array.map创建一个新数组，而array.forEach不创建一个新数组实例。

样品溶液

 const arr = [ {emailAddress: "xxx", squats: "0", steps: "4500", WorkoutDate: "12-5-2020", pullUps: "0"}, {emailAddress: "yyy", squats: "4000", steps: "0", WorkoutDate: "10-5-2020", pullUps: "0"}, {emailAddress: "zzz", WorkoutDate: "05-08-2020"} ]; arr.forEach((item) => { for (const property in item) { console.log(`${property}: ${item[property]}`); } })

Answer 2

有多种方法可以遍历数组的内容：

 const objects = [ { "name": "John" }, { "name": "Tess" }, { "name": "Tomi" } ]; // Foreach objects.forEach(currentObject => console.log(currentObject.name)); // For of for (const currentObject of objects ) { console.log(currentObject.name); } // For-loop for (let i = 0; i < objects.length; i++) { console.log(objects[i].name); }

Answer 3

 const arr = [{ emailAddress: "xxx", squats: "0", steps: "4500", WorkoutDate: "12-5-2020", pullUps: "0" }, { emailAddress: "yyy", squats: "4000", steps: "0", WorkoutDate: "10-5-2020", pullUps: "0" }, { emailAddress: "zzz", WorkoutDate: "05-08-2020" } ]; arr.forEach((arr, i, val) => { val[i] = Object.values(val[i]); }); console.log(arr);

Answer 4

你也可以这样做：

 var arr = [{ emailAddress: "xxx", squats: "0", steps: "4500", WorkoutDate: "12-5-2020", pullUps: "0" },{ emailAddress: "yyy", squats: "4000", steps: "0", WorkoutDate: "10-5-2020", pullUps: "0" }, { emailAddress: "zzz", WorkoutDate: "05-08-2020"}]; arr.forEach((val)=>{ for(let [key, value] of Object.entries(val)) { console.log(`Value of ${key} is ${value};`); } });