How do I create an boolean array and check if all boolean are true and then execute smth

Question

I have a boolean Array. I want to check if all of this booleans are true.

How can I print a message, if all of them are true?

public static boolean[] tubes = new boolean[9];

What have you tried? There are several ways this could be implemented. — Dave Newton, Mar 19 '21 at 20:19
I tried it with an for loop. An then checked it with if(Tubes[i] == true) System.out.println("All of them are true"); But this check every boolean and outputs that 9 times. I only want 1 output which says that all of them are true. I hope you understand sry for my english. — TechnikFabrik, Mar 19 '21 at 20:23
@TechnikFabrik The for loop should store the *aggregation* of values (and can break as soon as an unmatching value is found). — Dave Newton, Mar 19 '21 at 20:34

Montaser Sobaih · Accepted Answer · 2021-03-19T21:33:28.303

1

You can loop elements and store its result in a variable as shown below:-

boolean isTrue = false;
for (boolean bool : tubes) {
    isTrue = bool;
    if (!isTrue) {
       break;
    }
}

if (isTrue) {
  // print...
}

Another solution

boolean isTrue = true;
for (boolean bool : tubes) {
    isTrue &= bool;
}

if (isTrue) {
  // print...
}

edited Mar 19 '21 at 21:33

answered Mar 19 '21 at 20:25

Montaser Sobaih

305
2
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1

You could replace the loop body with `if (!(isTrue = bool)) break;`: this stops as soon as a false is found. – Andy Turner Mar 19 '21 at 20:36
@AndyTurner Done – Montaser Sobaih Mar 19 '21 at 20:45
1

@MontaserSobaih I didn't say you should remove your version. It is arguably less readable. I might present both as options (or even `isTrue = bool; if (!isTrue) break;` instead of the version with the inline assignment). – Andy Turner Mar 19 '21 at 21:26

score 0 · Answer 2 · answered Mar 19 '21 at 20:29

Do you mean like this?

    public boolean checkFunction(boolean[] Tubes) {
    //boolean[] Tubes = new boolean[9];
    boolean et = true; // by default, every member of the array is true

    for(int i=0; i < 9;i++) {
        if (Tubes[i] == false) { // if i find a false item then its false
            System.out.println("This is false: " + Tubes[i]);
            et = false;
        }
    }
    return et;
}

How do I create an boolean array and check if all boolean are true and then execute smth

2 Answers2