如何在一行上准确输入五个字符串，然后将每个字符串之间留有空格的字符串放出来？ 爪哇

Question

I want a user to input five letters on a single line (for example the word "hello") and have the output be "hello". I am able to do this with String.replace (as seen below) but I need to use printf and %s to do it .

Scanner scanner = new Scanner(System.in);
System.out.println("Enter five chatracters: ");
String charoutput = scanner.next();
String charoutput2 = charoutput.replace("", "       ");

System.out.println("You have entered: " +charoutput2);

Answer 1

You can use printf to print space for each character in string

String str = "hello";
    char[] ch =str.toCharArray();
    for (char c:ch) {
        System.out.printf("%2s", c);  // h e l l o
    }

or you can use Java 8 streams to do it in line

Arrays.stream(str.split("")).forEach(i->System.out.printf("%2s",i)); //h e l l o

Answer 2

There are multiple ways to solve this:

Using String.join :

String input = "Hello";
String result = String.join(" ", input.split(""));
// result now holds "H e l l o"

Using regex with replaceAll:

String input = "Hello";
String result = input.replaceAll(".","$0 ").trim();
// result now holds "H e l l o"

Using a loop:

String input = "Hello";
int length = input.length;
for(int i=0; i<length; i++)
  System.out.printf("%c%s", input.charAt(i), i<length ? " " : "");
// outputs "H e l l o"

Using printf :

String input = "Hello";
for(char c : input.toCharArray())
  System.out.printf("%2c", c);
// outputs " H e l l o" (NOTE the leading space!)

Try it online.

My preference would be the String.join , since it's basically a builtin of what you want to do.

Answer 3

Here is one of the ways you can do that:

Scanner scanner = new Scanner(System.in);
System.out.println("Enter five chatracters: ");
String charOutput = scanner.next();

String separatedChars = "";
for(char c: charOutput.toCharArray()) {
    separatedChars += c + " ";
} 

System.out.printf("You have entered: %s", separatedChars);

Here you iterate through each char of the received string and add it to the separatedChars variable followed by a space. Then, the result is printed using printf .