Mapping an array inside a loop

Question

I need to assign an object inside a loop. Here's my code :

let dataObj = {}
let dataArr = []
 , temp = []
while ( i < file.length ) {
 array[i].forEach(item => temp.push(item))
 dataObj.name = temp[0]
 dataObj.nim = temp[1]
 dataArr.push(dataObj)
 temp = []
 i++
}

Expected output:

// dataArr = [{name: panji, nim: 123}, {name: gifary, nim: 234}]

Reality :

// dataArr = [{name: gifary, nim: 234}, {name: gifary, nim: 234}]

I'm not sure how can I do this right. Does anybody know the way?

Thank you for your help!

• VLAZ: You are not mapping an array. You are just misusing .map instead of something more appropriate like .forEach.
• panji gemilang: It gave the same result with .forEach
• David Thomas: Can you show the initial array you're iterating over?
• VLAZ: Well, what's your input? The output being wrong doesn't make sense unless we know what data you operate on. It might be that you are doing this in reverse and you might need to iterate backwards or unshift instead of push

Answer 1

dataObj is a reference to the same object. You can do it without using a variable:

 dataArr.push({
 name: temp[0],
 nim : temp[1]
 })

• Anurag Srivastava: Glad to help, most probable reason would be a lack of information in the question, such as what is the input. So any answers would be considered guesswork till the question is more complete.

Answer 2

You are facing reference problem. Object set by reference will cause same data when you push to array because its same object with different variable name

while ( i < file.length ) {
 array[i].forEach(item => temp.push(item))
 // use new object instead
 let dataObj = {name: temp[0], nim: temp[1]};
 dataArr.push(dataObj)
 temp = []
 i++
}

Create new object instead or clone your object using this

let newObj = JSON.parse(JSON.stringify(dataObj);