如何使用for循环仅排除数组的json对象中的某些元素？

Question

我想调用函数checkIsObjectEmptyOrNot 仅当所有“name”、“age”、“class”字段不为空时。如果所有这些（没有 id 和 book_id）值都为 null，则该函数应返回 false。 id 和 book_id 应该从这个过滤过程中排除，因为 id 和 book_id 总是从 Laravel 后端获得一些价值。

 checkIsObjectEmptyOrNot(object){

        for (var key in object) {
            if (key != 'id' && key != 'book_id' && key != null) {
                break;
                return true;
            }
        }
        return false;
    }

我有一个类似的 Json 数组，

[
    {
         "id": 1,
         "book_id": 2,
         "name": "myname",
         "age": 25,
         "class":null,
    },
    {
        "id": 2,
        "book_id": 2,
        "name": "myname2",
        "age": 25,
        "class": null,
    },
    {
        "id": 3,
        "book_id": 2,
        "name": "myname3",
        "age": 25,
        "class": 10,
    },
]

Answer 1

您可能不需要为此添加新功能。 Array.filter 可以胜任。请参见下面的 sn-p。将返回所有有效项目。

const arr = [
 {
 "id":1,
 "book_id":2,
 "name":"myname",
 "age":25,
 "class":null,
 },
{
 "id":2,
 "book_id":2,
 "name":"myname2",
 "age":25,
 "class":null,
 },
{
 "id":3,
 "book_id":2,
 "name":"myname3",
 "age":25,
 "class":10,
 },
].filter((item)=>{
  return item.name && item.age && item.class
})

console.log(arr);

但如果你需要一个功能，这可以是它

const arr = [{
    "id": 1,
    "book_id": 2,
    "name": "myname",
    "age": 25,
    "class": null,
  },
  {
    "id": 2,
    "book_id": 2,
    "name": "myname2",
    "age": 25,
    "class": null,
  },
  {
    "id": 3,
    "book_id": 2,
    "name": "myname3",
    "age": 25,
    "class": 10,
  },
]

function checkIsObjectEmptyOrNot(object) {
     for (var key in object) {
        if (key !== 'id' && key !== 'book_id' && object[key] !== null)
            return true;
    }
    return false;
}

console.log(checkIsObjectEmptyOrNot(arr[0]));
console.log(checkIsObjectEmptyOrNot(arr[1]));
console.log(checkIsObjectEmptyOrNot(arr[2]));

如果所有name、age 和class 不是null 或undefined 或false 和true，则返回true

希望这会有所帮助:)

Answer 2

您可以尝试使用 forEach 。

    var arr = [
         {
         "id":1,
         "book_id":2,
         "name":"myname",
         "age":25,
         "class":null,
         },
        {
         "id":2,
         "book_id":2,
         "name":"myname2",
         "age":25,
         "class":null,
         },
        {
         "id":3,
         "book_id":2,
         "name":"myname3",
         "age":25,
         "class":10,
         },
        ]
         var flag = 0;
         arr.forEach(function(singleObject){
            for (let [key, value] of Object.entries(singleObject)) {
                if(singleObject[key] != _id || singleObject[key] != book_id){
                    if(singleObject[key] != null){
                     flag = 1;
                    }
                }   
}
});
   //if condition satisfies if all the value is null except _id and book_id
    if(flag == 0 ){
    //call function.
    checkIsObjectEmptyOrNot()

    }