I have a question about recursion

Question

I created a method in java called check that uses recursion to calculate something and return boolean.
My code didn't work when I just wrote
check(); in to method to make recursion, but it did work when I wrote: return check();.

Can someone explane me whats the difference?

Thank you:)

Answer 1

😂

Answer 2

Yes but its not where the recursion stops and the method returns a value. It is just where I need the method to call itself. Threre is another place where the method returns true or false after the calculation finished

Answer 3

I think you mean about the return symm(a); and the if(symm(a1)).
in this case, try to understand the if :
if(1234) means nothing. but
if(true) or if(false) return a condition.

Answer 4

The method should check if the array is symmetric.
For example the array {2, 4, 7, 8, 11, 13} is symmetric because 2+13 = 15, 4+11 = 15 and 7+8 = 15.

Answer 5

oh ok, but my languages are web languages. now it's okay. let me time

Answer 6

your prog works normally, why need you help ?

Answer 7

I got an exercise and it says that I must use recursion

Answer 8

in a time you just execute your function, in a second time you say to output result of your function

Answer 9

public class SYMM {

static int i = 0;
static int sum;

public static boolean symm(int[] a) {
if(i == 0) {
sum = a[0] + a[a.length-1];
}
if(sum == a[i] + a[a.length-i-1]) {
if(i+1 == a.length/2) {
return true;
}
i++;
return symm(a);
}
return false;
}

public static void main(String[] args) {

int[] a1 = {2, 3, 4, 6, 7, 8};

if(symm(a1)) {
System.out.println("Yes");
}
else{
System.out.println("No");
}
}

}

Answer 10

Because I still didn't understand why is it working when I write "return symm(a);" instead of just calling it simply "symm(a);"

Answer 11

oh I understand. why dont use you a for loop ?

Answer 12

can I have the code please ?

Answer 13

symm(a) execute the function and
return symm(a) return the result of the function (true or false)

Answer 14

This is recursion
https://www.sololearn.com/Discuss/1229035/?ref=app