如果键与数组值匹配，如何获取值

Question

I have written one array as below

const OBJECT = {
    '3': 'History And Social Sciences',
    '5': 'Humanities',
    '8': 'Global Studies And Social Impact',
    '10': 'Sanskrit'
};

var rou=[3,5,8,10];

I want to fetch the field values when keys are matching with values. Does anyone have any idea on it?

Answer 1

map over rou and get the value from OBJECT of that key:

 const OBJECT = { '3': 'History And Social Sciences', '5': 'Humanities', '8': 'Global Studies And Social Impact', '10': 'Sanskrit', }; var rou = [3, 5, 8, 10]; var values = rou.map(k => OBJECT[k]); console.log(values);

Answer 2

rou[0] is 3 , rou[1] is 5 and so on. What you want is to check if rou[0] that has the value 3, is key to you dictionary.

Answer 3

You can access the value from the object like this

var value = OBJECT.rou[0] 

Iterate 'rou' array and for each value of it find the corresponding value in the OBJECT

Answer 4

   Iterator<String> it = jsonObject.keys(); 
   List<Integer> list=new ArrayList();
   while(it.hasNext()){
   int key = it.next(); 
   list.add(key);
   }

Answer 5

Loop over the object properties and compare if the key is found in arr by indexOf if found get the value of that key.

 const OBJECT = {'3': 'History And Social Sciences','5': 'Humanities','8': 'Global Studies And Social Impact','10': 'Sanskrit','a': 'abc'}; var rou = [3, 5, 8, 10]; for (var property in OBJECT) { if (OBJECT.hasOwnProperty(property) && rou.indexOf(parseInt(property)) != -1) { console.log(OBJECT[property]); } }

You can also do it by iterating the array and if the element of array is present in the object get the value of that object

 const OBJECT = {'3': 'History And Social Sciences','5': 'Humanities','8': 'Global Studies And Social Impact','10': 'Sanskrit','a': 'abc'}; var rou = [3, 5, 8, 10]; rou.forEach(function(element) { if (OBJECT[element] != undefined) { console.log(OBJECT[element]); } });

Answer 6

With ramdajs' pick , it's easier.

R.pick(['a', 'd'], {a: 1, b: 2, c: 3, d: 4}); //=> {a: 1, d: 4}
R.pick(['a', 'e', 'f'], {a: 1, b: 2, c: 3, d: 4}); //=> {a: 1}

If you're interested, check its implementation

Answer 7

 const OBJECT = { '3': 'History And Social Sciences', '5': 'Humanities', '8': 'Global Studies And Social Impact', '10': 'Sanskrit' }; var rou=[3,5,8,10]; var res = Object.keys(OBJECT).reduce((acc, cur) => rou.indexOf(parseInt(cur)) !== -1 ? (acc.push(OBJECT[cur]), acc) : acc, []) console.log(res)