在Java readLine中防止空输入

Question

我想阻止用户提供空输入，这是我的代码

private void guessWord(){
    String input = readLine("Your guess: ");
    while(!isValidInput(input)){
        println("Your input is invalid, please try again.");
        input = readLine("Your guess: ");
    }
    char letter = input.charAt(0);
    letter = Character.toUpperCase(letter);
    if(!(subtituteLetter(letter))){
        println("There are no " + letter + "\'s in the word.");
        life -=1 ;
    }

}

我不想将空输入传递给我的 isValidInput ，那么如何阻止readLine接受来自用户的空输入？

Answer 1

您可以简单地强制用户在循环中输入非空字符串。

private void guessWord(){
    String input;
    do{
    input = readLine("Your guess: ");
    }
    while(input.isEmpty());

    while(!isValidInput(input)){
        println("Your input is invalid, please try again.");
        input = readLine("Your guess: ");
    }
    char letter = input.charAt(0);
    letter = Character.toUpperCase(letter);
    if(!(subtituteLetter(letter))){
        println("There are no " + letter + "\'s in the word.");
        life -=1 ;
    }
}

Answer 2

用这个循环替换你：

    while(input.isEmpty() || !isValidInput(input)){
        println("Your input is invalid, please try again.");
        input = readLine("Your guess: ");
    }