Modify while loop to execute at-least once

Question

doing some exam revision. One question is, Modifiy code to so that the loop will execute at-least once.

My Code :

int x = 0;
while (x < 10) {
   if (x % 2 != 0) {
       System.out.println(x);
   }
   x++;
}

Now i know while will loop while the condition is true, i know i cannot remove the x++ as this will give me infinite zeros. i think i would just remove the if statement and the brace related to it.

would you agree?

int x = 0;
while (x < 10) {
    System.out.println(x);
    x++;
}

Answer 1

Although this specific loop actually executes at least once even unchanged, that is not a property of a while-loop.

If the condition in the while-loop is not met, the loop never executes.

A do-while loop works almost the same way, except the condition is evaluated after execution of the loop, hence, the loop always executes at least once:

void Foo(bool someCondition)
{
    while (someCondition)
    {
        // code here is never executed if someCondition is FALSE
    }
}

on the other hand:

void Foo(bool someCondition)
{
    do 
    {
        // code here is executed whatever the value of someCondition
    }
    while (someCondition) // but the loop is only executed *again* if someCondition is TRUE
}

Answer 2

I would not agree, that would change the fundamental purpose of the loop (to emit every other number to stdout).

Look into converting to the do/while loop.

Answer 3

Whilst your solution has technically answered the question, I don't think it's what they were looking for (which isn't really your fault, and makes it a badly-worded question in my opinion). Given it's an exam question, I think what they're after here is a do while loop.

It works the same as a while loop except that the while condition is checked at the end of the loop - which means that it will always execute at least once.

---

Example:

while(condition){
    foo();
}

Here, condition is checked first, and then if condition is true , the loop is executed, and foo() is called.

Whereas here:

do{
    foo();
}while(condition)

the loop is executed once, foo() is called, and then condition is checked to know whether to execute the loop again.

---

More:

For further reading you might want to check out this or this tutorial on while , do while and for loops.

Answer 4

int x = 0;
        while (x <10){
        System.out.println(x);
            x++;
        }

Will work

EDIT: i think the others comments are rights too, the do/while loop will force one execution of the code

Answer 5

var x = 0;
do {
    if (x % 2 != 0) System.out.println(x);
    x++;
} while (x < 10);