while循环不执行else语句并重复循环

Question

When compiled upon not entering the right selection it doesnt display to re-enter or repeat the loop

int counterA = 0;
while (counterA < 0) {
    if (conversionSelection.equalsIgnoreCase("binary"))
            counterA++;
    if (conversionSelection.equalsIgnoreCase("octal"))
            counterA++;
    else System.out.println("Error. Please enter weither to convert the Hex to Octal or Binary:");
        conversionSelection = keyboard.nextLine();
    }

Answer 1

The loop should not execute at all since the condition fails right from the get-go.

There is also a dangling else statement. So you need to have an else-if for your second if statement if you want the else to properly execute. While it may not currently produce errors, it is an important skill to prevent dangling 'else's'.

Answer 2

Your code will never enter the while loop since counterA = 0 and the while loop condition is for it to be < 0 . You want counterA to be less than zero, or the condition to include counterA 's value in its set (eg while (counterA <= 0) ).

Answer 3

因为0不小于0，所以此循环永远不会开始。