CODEWITHSUNDEEP
javascriptarraysfunctionobjectfor-loop
Zr Classic
Zr Classic

Reputation: 313

if/else statement in map function?

I am here want to use map function in javascript to loop a type data array,but i get error for these syntax below :

function porti(scores) {
const test = scores.map(pass, fail) => {
    if (scores < 75){
      test.fail
    } else {
      test.pass
    }
    return {pass, fail}
  }

}

output must be, if scores < 75 : fail, else : pass

console.log(porti([80, 45, 90, 65, 74, 100, 85, 30]));
// { pass: [ 80, 90, 100, 85 ], fail: [ 45, 65, 74, 30 ] }

console.log(porti([]));
// { pass: [], fail: [] }

Upvotes: 1

Views: 8200

Answers (3)

adam.k
adam.k

Reputation: 632

As mentioned above .map() should best be saved for when you are looking to return an array by manipulating a previous array. If you don't wish to use a vanilla for loop. You could try this

const testScores = [...someArray of numbers]
function porti(tesScores) {    
const result = {
   pass: [],
   fail: []
}
    for (let score of testScores) {
        if (score < 75) {
           result.fail.push(score)
         } else {
           result.pass.push(score)
         }
  return result      
}}

Upvotes: 0

Get Off My Lawn
Get Off My Lawn

Reputation: 36299

I think reduce would be better for this situation. This will allow us to reduce the array to an object of two item arrays.

let items = [80, 45, 90, 65, 74, 100, 85, 30]

let result = items.reduce((obj, item) => {
  item < 75 ? obj.fail.push(item) : obj.pass.push(item)
  return obj
}, {pass:[], fail:[]})

console.log(result)

If you wanted to use filter you could...

let items = [80, 45, 90, 65, 74, 100, 85, 30]

let result = {
  pass: items.filter(i => i >= 75),
  fail: items.filter(i => i < 75)
}

console.log(result)

And here is how we can do it with forEach...

let items = [80, 45, 90, 65, 74, 100, 85, 30]

let result = {pass:[], fail:[]}
items.forEach(itm => itm < 75 ? result.fail.push(itm) : result.pass.push(itm))

console.log(result)

Upvotes: 4

Nina Scholz
Nina Scholz

Reputation: 386560

You could integrate the check as ternary for getting the key for pushing.

function porti(scores) {
    var result = { pass: [], fail: [] },
        score;

    for (score of scores) {
        result[score < 75 ? 'fail': 'pass'].push(score);
    }
    return result
}

console.log(porti([80, 45, 90, 65, 74, 100, 85, 30]));
console.log(porti([]));
.as-console-wrapper { max-height: 100% !important; top: 0; }

Upvotes: 2

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