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arraysjsonangularobjectif-statement
JavaDeveloper
JavaDeveloper

Reputation: 102

JSON Array element comparion with Java Script Array in Angular 2

I am working on Angular 2 with type script and came up with a very peculiar problem. I have a number array named empIds as

empIds = {1,5,6,9,2}

I have (a JSON Array) named empDetails (please note employeeId is string here)as 

empDetails [{"employeeId":"1","employeeName":"Jhon"},
            {"employeeId":"2","employeeName":"Ron"},
            {"employeeId":"3","employeeName":"Van"}]

Now i have to find out the only JSON objects who's id match in number array. Here is what i wrote

for(let i=0;i<empDetails.length;i++){
if(empIds.indexOf(empDetails[i].employeeId)==0 ){
//Employee ID is present save that JSON object to some other JSON Array
i should get details for matched id (1 and 2)
}else{
//Did not match
do nothing
}
}

i did put console.log for both if and else. My loop never matches it always goes to else condition? Is there any possible solution?

Upvotes: 0

Views: 56

Answers (3)

cyberpirate92
cyberpirate92

Reputation: 3166

var filtered = empDetails.filter( (e) => empIds.indexOf(parseInt(e.employeeId)) >= 0 );

If you don't care about support for Internet explorer, you can also use includes() (See answer by Hopless)

Upvotes: 0

Ales
Ales

Reputation: 56

const newArray = empDetails.filter(item => empIds.includes(item.employeeId));

I think this is an ok way to get a new array with all the objects from empDetails that have the employeeId in empIds.

.includes() => returns true or false if the empIds contains the employeeId

.filter() => returns all the objects that were true on the include call

empIds = [2];

empDetails = [{"employeeId":1,"employeeName":"Jhon"},
            {"employeeId":2,"employeeName":"Ron"},
            {"employeeId":3,"employeeName":"Van"}]

with my code the new array would be this

[{"employeeId":2,"employeeName":"Ron"}]

because only employeeId = 2 is in empIds table

Upvotes: 0

Rohit Ramname
Rohit Ramname

Reputation: 834

The code logic is incorrect. Check index if its greater than -1 Should be as below 

 let empIds = [1, 5, 6, 9, 2];
    let empDetails = [{ "employeeId": 1, "employeeName": "Jhon" },
    { "employeeId": 2, "employeeName": "Ron" },
    { "employeeId": 3, "employeeName": "Van" }]
    for (let i = 0; i < empDetails.length; i++) {
      if (empIds.indexOf(empDetails[i].employeeId) > -1) {
        console.log("found");
        console.log(empDetails[i])
      }
    }

Upvotes: 1

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