你能建议我在哪里犯错:
  public static char[] replaceSpaces(String string){
    int length = string.length();
    int spaceCount = 0;
    for(int i =0; i<=length-1;i++){if(string.charAt(i)==' '){spaceCount++;}}
    int index = length + spaceCount*2;
    char[] charString = new char[index];
    int k=0;
    for(int i=0;i<index-1;i++){
        if(string.charAt(k) == ' '){
            charString[i] = '%';
            charString[i+1] = '2';
            charString[i+2] = '0';
            i = i +2;
            k=k+1;}
        else
            charString[i] = string.charAt(k);
            k++;
    }
    return charString;}
}
它输出wa%20cf而我想要“wa%20dcf”作为输出。基本上我用“%20”替换每个空格。此外,此代码不适用于两个或多个空格。