How do I apply an if statement condition to every element on an arraylist?

Question

Basically I want to know how to apply an if condition to every element of an arraylist. Here's my code.

   System.out.println("Type positive integers less than 40: ");

    ArrayList<Integer> inRay = new ArrayList<Integer>();
    Scanner sc = new Scanner(System.in);
    while (sc.hasNext())
    {
        inRay.add(sc.nextInt());
    }

    //this is where the problem starts//

    int i;
    if (inRay.get(i) > 40)
    {
        System.out.println("You had one job.");
        System.exit(0);
    }

I would like to apply an if condition where if a value in the array list is over 40, it exits.

...or any other loop. Maybe start [here](http://www.tutorialspoint.com/java/java_loop_control.htm). — Pshemo, May 01 '14 at 00:03
Do you want to apply the if check as it is entered or once all input has been entered? — cyber-monk, May 01 '14 at 00:04

score 0 · Answer 1 · answered May 01 '14 at 00:06

Replace the line where you are declaring 'i' with a for loop that starts from 0 and goes up to iRay.size().

for(int i=0; i<iRay.size(); i++)

In this for loop, the portion before the first semi-colon, declare and initialize a counter variable to 0. After the first semi-colon is the condition up to which the loop should repeat, and after the second semi-colon, is the increment of the counter.

score 0 · Answer 2 · answered May 01 '14 at 00:07

You need to iterate over the ArrayList like this:

for (int i : inRay)
    if (i > 40) {
        System.out.println("You had one job.");
        System.exit(0);
    }

In general, if you want to do something for every element of an array list, do this:

for (Type t : list) {
    // do something involving t
}

You need the actual type of the array list elements instead of Type.

How do I apply an if statement condition to every element on an arraylist?

2 Answers2