How to test if a string is empty or blank in java? Below is my code, I want to create a loop that keeps running as long as the input is not empty Scanner input = new Scanner(System.in); do { System.out.print("Please type in a sentence: "); String newSentence = input.nextLine(); pigLatin(newSentence); }while(!input.isEmpty()); But the java says: Translate.java:10: ??: ????? }while(!input.isEmpty()); ^ ??: ?? isEmpty() ??: ???Scanner??? input 1 ??? How to solve that?