代替 ！ Java中的空字符

Question

With the given input test!! test!!! test !!! test!! test!!! test !!! the program below should return test! test! test ! test! test! test ! by removing all but one of '!'or '?' in a row.

However the program outputs it like this: test! test! test ! ! test! test! test ! !

How would I remove the extra '!' or '?' characters?

StringBuilder sb = new StringBuilder(input);

for (int i = 0; i < input.length() - 1; i++)
{   
    // Does string contain '?' or '!'
    if (input.charAt(i) == '?' || input.charAt(i) == '!') {
        // TODO: Remove extra characters
    }
    else
    {
         sb.setCharAt(i, input[i]);
    }
}

System.out.println(sb.toString());

Answer 1

Hints:

1. There is no such thing as an empty character. So sb.setCharAt(i, empty); is actually replacing the character at position i with a NON-EMPTY character. It looks like its is a space character; ie Unicode / ASCII SP .

2. You can use deleteCharAt(1) to remove a character at position i of a StringBuilder . But beware that removing the character at position i causes the characters at i + 1 , i + 2 and so on to change position . You need to take account of that in your code.