CODEWITHSUNDEEP
javascripttypescript
Bharath Bharath
Bharath Bharath

Reputation: 99

How to check for a non existing value in a map typescript?

I have the below map in typescript:

myMap = {"a" => 1, "b" => 2, "c" => 4, "d" => 5}

The values can be 1 , 2 , 3, 4, or 5 only.

I need to check for the values in the myMap from 1 to 5 and if any of the value is missing, i want to log it and exit the loop. Eg: In the above map, value 3 is missing. So, i would want to log that value.

Can anyone let me know, how this could be achieved in typescript ?

Upvotes: 0

Views: 1057

Answers (3)

adiga
adiga

Reputation: 35222

You could create a Set of the values in Map. Then filter the numbers array and check if the set has each number

const numbers = [1, 2, 3, 4, 5],
      map = new Map([ ["a", 1], ["b", 2], ["c", 4] ]),
      set = new Set(map.values()),
      missing = numbers.filter(n => !set.has(n))

console.log(missing)

Upvotes: 1

Durgesh
Durgesh

Reputation: 205

Taking into consideration that values are 1 to 5, you could change array as well and use some other values with specific range and use it with map with this -

var map = new Map();
map.set('a', 1)
map.set('b', 2)
map.set('c',4) 
map.set('d', 5)

var arr = [];

for(var singleVal of map.values()) arr.push(singleVal)
    
var originalArr =  [ 1, 2, 3, 4, 5]; // taking into consideration that you have some original array like this, where '3' is present

for(var i=0; i<originalArr.length; i++)
    if(!arr.includes(originalArr[i]))
    {
        console.log(originalArr[i]);
        break;
    }

Upvotes: 0

Ilijanovic
Ilijanovic

Reputation: 14904

That something more javascript specific then typescript.

var myMap = new Map();
myMap.set("a", 1);
myMap.set("b", 2);

let hasThree = [...myMap.values()].includes(3);

console.log(hasThree);

You can use .values() and spread it into an array and use then .includes

enter image description here

Here is an image that shows all methods of the Map prototype.

Upvotes: 0

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