How to loop through object - JavaScript

Question

targetId = [313,309,307,318,317]

data={
313:[{time:..., value:...},
{time:..., value:...},
{time:..., value:...},
{time:..., value:...},
],
303:[{time:..., value:...},
{time:..., value:...},
{time:..., value:...},
{time:..., value:...},
],
309:[{time:..., value:...},
{time:..., value:...},
{time:..., value:...},
{time:..., value:...},
],
307:[{time:..., value:...},
{time:..., value:...},
{time:..., value:...},
{time:..., value:...},
],
322:[{time:..., value:...},
{time:..., value:...},
{time:..., value:...},
{time:..., value:...},
],
318:[{time:..., value:...},
{time:..., value:...},
{time:..., value:...},
{time:..., value:...},
],
317:[{time:..., value:...},
{time:..., value:...},
{time:..., value:...},
{time:..., value:...},
],
311:[{time:..., value:...},
{time:..., value:...},
{time:..., value:...},
{time:..., value:...},
]
}

Can someone help me please. So I need to loop through data object and if data property match with one of number from targetId list then I need to extract all values from that property and store them in separate list.

for (let i = 0; i < targetId.length; i++) {
if(targetId[i] === data.[property])
separateList.push(data.[property].value)
}

I guess something like this should maybe do it but need to somehow add looping through object

Answer 1

Array of arrays

You can Array#map over targetId and pick items from data and extract values as an array again using .map() :

targetId.map(
  id => data[id].map(({value}) => value)
);

Demo:

 const targetId = [313,309,307,318,317] const data = { 313:[ {time:3131, value:3131}, {time:3132, value:3132}, {time:3133, value:3133}, {time:3134, value:3134}, ], 303:[ {time:3031, value:3031}, {time:3032, value:3032}, {time:3033, value:3033}, {time:3034, value:3034}, ], 309:[ {time:3091, value:3091}, {time:3092, value:3092}, {time:3093, value:3093}, {time:3094, value:3094}, ], 307:[ {time:3071, value:3071}, {time:3072, value:3072}, {time:3073, value:3073}, {time:3074, value:3074}, ], 322:[ {time:3221, value:3221}, {time:3222, value:3222}, {time:3223, value:3223}, {time:3224, value:3224}, ], 318:[ {time:3181, value:3181}, {time:3182, value:3182}, {time:3183, value:3183}, {time:3184, value:3184}, ], 317:[ {time:3171, value:3171}, {time:3172, value:3172}, {time:3173, value:3173}, {time:3174, value:3174}, ], 311:[ {time:3111, value:3111}, {time:3112, value:3112}, {time:3113, value:3113}, {time:3114, value:3114}, ] } const result = targetId.map( id => data[id].map(({value}) => value) ); console.log(result);

Single array

If you want a single array of values, not an array of array of values, then use Array#flatMap :

targetId.flatMap(
  id => data[id].map(({value}) => value)
);

Demo:

 const targetId = [313,309,307,318,317] const data = { 313:[ {time:3131, value:3131}, {time:3132, value:3132}, {time:3133, value:3133}, {time:3134, value:3134}, ], 303:[ {time:3031, value:3031}, {time:3032, value:3032}, {time:3033, value:3033}, {time:3034, value:3034}, ], 309:[ {time:3091, value:3091}, {time:3092, value:3092}, {time:3093, value:3093}, {time:3094, value:3094}, ], 307:[ {time:3071, value:3071}, {time:3072, value:3072}, {time:3073, value:3073}, {time:3074, value:3074}, ], 322:[ {time:3221, value:3221}, {time:3222, value:3222}, {time:3223, value:3223}, {time:3224, value:3224}, ], 318:[ {time:3181, value:3181}, {time:3182, value:3182}, {time:3183, value:3183}, {time:3184, value:3184}, ], 317:[ {time:3171, value:3171}, {time:3172, value:3172}, {time:3173, value:3173}, {time:3174, value:3174}, ], 311:[ {time:3111, value:3111}, {time:3112, value:3112}, {time:3113, value:3113}, {time:3114, value:3114}, ] } const result = targetId.flatMap( id => data[id].map(({value}) => value) ); console.log(result);

Only existing results

If targetId might have items that aren't in data , then you can Array#filter and then .map() / .flatMap() :

targetId
    .filter(id => id in data)
    .map(id => data[id].map(({value}) => value))

Demo:

 const targetId = [313,309, 9001, 307,318,317, 42] const data = { 313:[ {time:3131, value:3131}, {time:3132, value:3132}, {time:3133, value:3133}, {time:3134, value:3134}, ], 303:[ {time:3031, value:3031}, {time:3032, value:3032}, {time:3033, value:3033}, {time:3034, value:3034}, ], 309:[ {time:3091, value:3091}, {time:3092, value:3092}, {time:3093, value:3093}, {time:3094, value:3094}, ], 307:[ {time:3071, value:3071}, {time:3072, value:3072}, {time:3073, value:3073}, {time:3074, value:3074}, ], 322:[ {time:3221, value:3221}, {time:3222, value:3222}, {time:3223, value:3223}, {time:3224, value:3224}, ], 318:[ {time:3181, value:3181}, {time:3182, value:3182}, {time:3183, value:3183}, {time:3184, value:3184}, ], 317:[ {time:3171, value:3171}, {time:3172, value:3172}, {time:3173, value:3173}, {time:3174, value:3174}, ], 311:[ {time:3111, value:3111}, {time:3112, value:3112}, {time:3113, value:3113}, {time:3114, value:3114}, ] } const result = targetId.filter(id => id in data).map(id => data[id].map(({value}) => value)); console.log(result);