Add to ListArray from Array

Question

For an array, how can i take all the values at even indexes and add to nameArray and all the values at odd indexes and add to scoreArray? I got this code but it isn't working.

String[] inputArray = {"john", "10", "frank", "14"}

for (int j = 0; j == inputArray.length; j++) {
    if ((j % 2) == 0) {
        nameArr.add(inputArray[j]);
        } else {
        scoreArr.add(inputArray[j]);
    }
}

Do I understand right you want to add the elements of inputArray? But then why use split2[]? — Meno Hochschild
– Meno Hochschild, Commented Jan 2, 2014 at 22:25
sorry just changed the name of the array to inputArray for comfort reading, just failed to change it all, but it's done now. — Kæmpe Klunker
– Kæmpe Klunker, Commented Jan 2, 2014 at 22:36

Alexis C. · Accepted Answer · 2014-01-02 22:31:03Z

6

You probably mean for (int j = 0; j < inputArray.length; j++)

j == inputArray.length is evaluated to false at the first iteration so your loop doesn't run.

However, you could get rid of the if statement (assuming that your inputArray always contains a name associated a score, i.e always contains pair values) :

for (int j = 0; j < inputArray.length; j+=2) {
    nameArr.add(inputArray[j]);
    scoreArr.add(inputArray[j+1]);
}

Or you could also use a Map<String, Integer> to associate each name with its corresponding score (assuming names are unique) :

for (int j = 0; j < inputArray.length; j+=2) 
     m.put(inputArray[j], Integer.parseInt(inputArray[j+1]));

edited Jan 2, 2014 at 22:31

answered Jan 2, 2014 at 22:25

Alexis C.

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2 Comments

But I'm Not A Wrapper Class Over a year ago

Why you got to beat me to it? |=^P

Alexis C. Over a year ago

@user3052244 You can read this for more informations about the for statement, docs.oracle.com/javase/tutorial/java/nutsandbolts/for.html

hichris123 · Accepted Answer · 2014-01-02 22:27:08Z

1

You probably mean to have a < in your loop and not a == and also, try using inputArray and not split2[] like this:

for (int j = 0; j < inputArray.length; j++) {
    if ((j % 2) == 0) {
        nameArr.add(inputArray[j]);
        } else {
        scoreArr.add(inputArray[j]);
    }
}

answered Jan 2, 2014 at 22:27

hichris123

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Comments

Paul Harris · Accepted Answer · 2014-01-02 22:27:13Z

1

What you want to do is look through each element in the array, to do this you want to go through every element starting at 0 and ending at the lengthof the array -1 (because arrays are 0 indexed). Once you are in the loop you want to check if it is an even or odd number using the modulo operator.

for (int j = 0; j < inputArray.length; j++){
    if ((j % 2) == 0) {
        nameArr.add(inputArray[j];
    } else {
        scoreArr.add(inputArray[j];
    }
}

answered Jan 2, 2014 at 22:27

Paul Harris

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