使用JAVASCRIPT将名称值对添加到JSON中的数组对象

Question

I want to implement this : "Check the key name default is available or not, if available then add one more key in same object. => ("pin" : 91) " on the json given below. I have tried the following code.

var myObj = {
     "data": [{
         "code": "EN",
         "language": "English",
         "content_available": true,
         "isdefault": true
     }, {
         "code": "AR",
         "language": "Arabic",
         "content_available": true,
         "isdefault": false,
                "default" : true

     }, {
         "code": "BR",
         "language": "Brazilian Portuguese",
         "content_available": true,
         "isdefault": false
     }, {
         "code": "CN",
         "language": "Simplified Chinese",
         "content_available": true,
         "isdefault": false,
                "default" : true
     }, {
         "code": "TW",
         "language": "Traditional Chinese",
         "content_available": true,
         "isdefault": false
     }, {
         "code": "DE",
         "language": "German",
         "content_available": true,
         "isdefault": false
     }, {
         "code": "ES",
         "language": "Spanish",
         "content_available": true,
         "isdefault": false
     }, {
         "code": "FR",
         "language": "French",
         "content_available": true,
         "isdefault": false
     }, {
         "code": "JP",
         "language": "Japanese",
         "content_available": true,
         "isdefault": false,
                 "default" : true
     }, {
         "code": "RU",
         "language": "Russian",
         "content_available": false,
         "isdefault": false
     }],
     "success": true
 }
function addKey(k) {
  for (var key in myObj.data) {
    if (myObj["data"][key] === k) {
      myObj["data"][key]["pin"] = "91";
    }
  }
}
addKey("default");
console.log(myObj);

Answer 1

function checkForKey(obj, key) {
    for (var i = 0; i < obj.data.length; i++) {
        if (obj.hasOwnProperty(obj.data[i]) && obj.data[i][key] !== undefined) {
            obj.data[i].pin = 91;
        }
    }
}

checkForKey(myObj, 'default');

First, we get the data key. Since it's an array we iterate over it. Then, we check if default key has a defined value or not and add the key pin only when it has been defined with any value.

Answer 2

All you need to do is loop through the key names and if not present, create it. But, keep your types in mind. for/in is for iterating objects, not arrays and forEach() is preferred for arrays.

 var myObj = { "data": [{ "code": "EN", "language": "English", "content_available": true, "isdefault": true }, { "code": "AR", "language": "Arabic", "content_available": true, "isdefault": false, "default" : true }, { "code": "BR", "language": "Brazilian Portuguese", "content_available": true, "isdefault": false }, { "code": "CN", "language": "Simplified Chinese", "content_available": true, "isdefault": false, "default" : true }, { "code": "TW", "language": "Traditional Chinese", "content_available": true, "isdefault": false }, { "code": "DE", "language": "German", "content_available": true, "isdefault": false }, { "code": "ES", "language": "Spanish", "content_available": true, "isdefault": false }, { "code": "FR", "language": "French", "content_available": true, "isdefault": false }, { "code": "JP", "language": "Japanese", "content_available": true, "isdefault": false, "default" : true }, { "code": "RU", "language": "Russian", "content_available": false, "isdefault": false }], "success": true } function addKey(k) { // myObj.data is an array. for/in loops should not be used on arrays // But forEach() is preferred on arrays myObj.data.forEach(function(obj){ // Each array element is an object. We need to loop that object. // for/in loops are for objects for(var prop in obj){ // Is the current property (key) name the same as the provided argument ("default") if(prop === k){ // Add new key/value to the object obj["pin"] = "91"; } } }); } addKey("default"); console.log(myObj);