Parse this Json response and loop through the array in JavaScript

Question

There are many post about this but I can't figure this one out. This is the json response from an Ajax function:

var obj = {
    "3901": 10,
    "3900": 3,
    "3902": 9,
    "3899": 2,
    "3274": 4,
    "3257": 9.5,
    "3883": 12,
    "3881": "12",
    "3876": 3,
    "3267": 14,
    "3258": 2.5,
    "3260": 13.5,
    "3259": 6.5,
    "3264": 4.5,
    "3268": 2,
    "3273": 5.5,
    "3266": 17,
    "3270": 9,
    "3271": 8,
    "3275": 2,
    "3263": 2.5,
    "3261": 2.5,
    "3265": "37",
    "3281": 3,
    "3277": 7.5,
    "3278": 0.5,
    "3276": 7,
    "3898": 8,
    "3891": 7,
    "3293": 1,
    "3895": 1,
    "3256": 2,
    "3903": 10,
    "3840": 2,
    "3886": 11,
    "3884": 8,
    "3872": 2,
    "3874": 4,
    "3284": 1.5,
    "3302": 1.25,
    "3304": 5,
    "3306": 2,
    "3329": 1.5,
    "3330": 2,
    "3333": 6,
    "3335": 7.5,
    "3327": 1,
    "3934": 8,
    "3935": 9,
    "3939": 1,
    "3933": 3,
    "3937": 1,
    "3322": 3.5,
    "3890": 1,
    "3878": 5,
    "3880": 4,
    "3879": 1,
    "3889": 2,
    "3852": 2,
    "3877": 2
}

I have a this of ids: 3902, 3883, 4567 and 3878

All I need is to loop through the those 4 ids and check if those are in the json response and if they are get the value associated to it and if not return 0. For example:

3902 will return 9 and 4567 will return 0

Thanks.

Answer 1

You can use a foreach

j={"3901":10,"3900":3,"3902":9,"3899":2,"3274":4,"3257":9.5,"3883":12,"3881":"12","3876":3,"3267":14,"3258":2.5,"3260":13.5,"3259":6.5,"3264":4.5,"3268":2,"3273":5.5,"3266":17,"3270":9,"3271":8,"3275":2,"3263":2.5,"3261":2.5,"3265":"37","3281":3,"3277":7.5,"3278":0.5,"3276":7,"3898":8,"3891":7,"3293":1,"3895":1,"3256":2,"3903":10,"3840":2,"3886":11,"3884":8,"3872":2,"3874":4,"3284":1.5,"3302":1.25,"3304":5,"3306":2,"3329":1.5,"3330":2,"3333":6,"3335":7.5,"3327":1,"3934":8,"3935":9,"3939":1,"3933":3,"3937":1,"3322":3.5,"3890":1,"3878":5,"3880":4,"3879":1,"3889":2,"3852":2,"3877":2}
se=[3902, 3883, 4567 , 3878]
res=[]
se.forEach(s=>{
  res.push({[s]:j[s]||0})
})
console.log(res)

Answer 2

I think you already have a valid JSON here.

let data = {"3901":10,"3900":3,"3902":9,"3899":2,"3274":4,"3257":9.5,"3883":12,"3881":"12","3876":3,"3267":14,"3258":2.5,"3260":13.5,"3259":6.5,"3264":4.5,"3268":2,"3273":5.5,"3266":17,"3270":9,"3271":8,"3275":2,"3263":2.5,"3261":2.5,"3265":"37","3281":3,"3277":7.5,"3278":0.5,"3276":7,"3898":8,"3891":7,"3293":1,"3895":1,"3256":2,"3903":10,"3840":2,"3886":11,"3884":8,"3872":2,"3874":4,"3284":1.5,"3302":1.25,"3304":5,"3306":2,"3329":1.5,"3330":2,"3333":6,"3335":7.5,"3327":1,"3934":8,"3935":9,"3939":1,"3933":3,"3937":1,"3322":3.5,"3890":1,"3878":5,"3880":4,"3879":1,"3889":2,"3852":2,"3877":2};

let arr = [3902, 3883, 4567 , 3878];

let ans = arr.map( i => {
  if(data[i] === undefined) {
   console.log(0);
   return 0;
  }
  else {
   console.log(data[i]);
   return data[i];
 }
});

ans is the required array .

Answer 3

var jsonObject = {3256: 2, 3257: 9.5, 3258: 2.5, 3259: 6.5, 3260: 13.5, 3261: 2.5, 3263: 2.5, 3264: 4.5, 3265: "37", 3266: 17, 3267: 14, 3268: 2, 3270: 9, 3271: 8, 3273: 5.5, 3274: 4, 3275: 2, 3276: 7, 3277: 7.5, 3278: 0.5, 3281: 3, 3284: 1.5, 3293: 1, 3302: 1.25, 3304: 5, 3306: 2, 3322: 3.5, 3327: 1, 3329: 1.5, 3330: 2, 3333: 6, 3335: 7.5, 3840: 2, 3852: 2, 3872: 2, 3874: 4, 3876: 3, 3877: 2, 3878: 5, 3879: 1, 3880: 4, 3881: "12", 3883: 12, 3884: 8, 3886: 11, 3889: 2, 3890: 1, 3891: 7, 3895: 1, 3898: 8, 3899: 2, 3900: 3, 3901: 10, 3902: 9, 3903: 10, 3933: 3, 3934: 8, 3935: 9, 3937: 1, 3939: 1}

var ids = [3902, 3883, 4567, 3878];

for(var i =0; i < ids.length; i++)
{  
   if(temp1.hasOwnProperty(ids[i])) //to check propery exist in JSON object
   { 
      console.log(temp1[ids[i]]) //to read value from JSON object
    }
 }

Answer 4

You can put all the ids into an array called ids, then use .map() on that array. For each id within the array, you can look it up in your object using obj[id]. If it doesn't exist, it will return undefined. If this occurs, you can use a default of 0 by using an ||:

See example below:

const obj = {"3901":10,"3900":3,"3902":9,"3899":2,"3274":4,"3257":9.5,"3883":12,"3881":"12","3876":3,"3267":14,"3258":2.5,"3260":13.5,"3259":6.5,"3264":4.5,"3268":2,"3273":5.5,"3266":17,"3270":9,"3271":8,"3275":2,"3263":2.5,"3261":2.5,"3265":"37","3281":3,"3277":7.5,"3278":0.5,"3276":7,"3898":8,"3891":7,"3293":1,"3895":1,"3256":2,"3903":10,"3840":2,"3886":11,"3884":8,"3872":2,"3874":4,"3284":1.5,"3302":1.25,"3304":5,"3306":2,"3329":1.5,"3330":2,"3333":6,"3335":7.5,"3327":1,"3934":8,"3935":9,"3939":1,"3933":3,"3937":1,"3322":3.5,"3890":1,"3878":5,"3880":4,"3879":1,"3889":2,"3852":2,"3877":2};

const ids = [3902, 3883, 4567, 3878];
const res = ids.map(id => obj[id] || 0);
console.log(res);