While loop repeats even if conditions are met

[username123]

What the title says. Here's my code:

Java:

System.out.println("Enter your payment method (supported: Visa, Mastercard, Paypal, cash");         String payment = input.next();         do         {           System.out.println("Invalid payment method.");           System.out.println("Enter your payment method (supported: Visa, Mastercard, Paypal, cash");           payment = input.next();         } while(!payment.equals("visa")||!payment.equals("Visa")||!payment.equals("mastercard")||!payment.equals("Mastercard")||!payment.equals("paypal")||!payment.equals("Paypal")||!payment.equals("cash")||!payment.equals("Cash"));

[Zren]

Use payment.equalsIgnoreCase("visa") instead of doing 2^(lengthOfString) comparisions to check all possibilities.

do {} while(); loops will always run once. It will not check the exit condition until the end of the first iteration.