How would i parseInt this

Question

i have tried like this

public Set<String> getEvens() {
    Set<String> evens = new TreeSet<String>();
    for (String a : list) {
        if (a % 2 == 0) {
            int x = Integer.parseInt(a);
            evens.add(x);
        }
    }
}

and this

public Set<String> getEvens() {
    Set<String> evens = new TreeSet<String>();
    for (String a : list) {
        int x = Integer.parseInt(a);
        if (a % 2 == 0) {
            evens.add(a);
        }
    }
}

but neither work and I'm not sure what else to try. I haven't used parseInt in a while and might be doing it wrong also

These are the errors I get:

error: bad operand types for binary operator '%'
error: no suitable method found for add(int)

@Prateek the first boils down to "can't mod a string" and the second is "undefined variable `a`". — Kevin, Sep 23 '13 at 22:50
@Kevin I knew that but wanted him to know that. We can point out his mistake once not always. Its better if he can pinpoint this on his own in the future — Prateek, Sep 23 '13 at 22:51
if (a%2==0) I believe a is a String.. I don't think you can do that. — porfiriopartida, Sep 23 '13 at 22:55

score 3 · Accepted Answer · answered Sep 23 '13 at 22:50

The second will almost work, it's just your parseInt is not within the for's curly braces, you will also need to use % on x (the int), not a (the String).

public Set<String> getEvens()
{
    Set<String> evens = new TreeSet<String>();
    for (String a : list)
    {
        int x =Integer.parseInt(a);
        if (x % 2==0)
        {
            evens.add(a);
        }
    }
}

score 0 · Answer 2 · answered Sep 23 '13 at 22:49

0

The second one is right, except use x%2 instead of a%2

answered Sep 23 '13 at 22:49

ia.solano

548
3
10
23

score 0 · Answer 3 · 2013-09-23T22:57:01.183

0

Operator % works only on numeric types in Java. Modify your second solution like this:

if (x % 2 == 0) {
    evens.add(a);
}

There is x instead of a in the if-condition.

edited Sep 23 '13 at 22:57

answered Sep 23 '13 at 22:50

score 0 · Answer 4 · answered Sep 23 '13 at 22:56

public Set<String> getEvens(List<String> list) {
    Set<String> evens = new TreeSet<String>();
    // modify for(String a:list){
    for (String a : list) {
        int x = Integer.parseInt(a);
        {
            //modify if (a % 2 == 0) {
            if (x % 2 == 0) {
                evens.add(a);
            }
        }
    }
    // modify add this }

}

score 0 · Answer 5 · edited May 23 '17 at 12:11

0

Both examples have a different error, but they are unrelated to parsing int.

Example 1: events.add(x), events takes Strings while x is int.
Example 2. a%2 is wrong, a is String.

Learning how to read stacktraces is fundamental in Java and would easily have helped you here: What is a stack trace, and how can I use it to debug my application errors?

edited May 23 '17 at 12:11

Community

1
1

answered Sep 23 '13 at 22:58

Homyk

364
2
7

How would i parseInt this

5 Answers5