Hey there! Let's break this down step by step since you're just starting out with Java—this is a great practice problem for getting comfortable with loops and string indices.

First, let's spot the pattern in your desired output: you're taking the original string "Jamaica" and repeatedly removing the first character, then printing each resulting substring separated by spaces. So:

• Start with the full string: Jamaica
• Remove first character: amaica
• Remove first character again: maica
• ... and so on until we're left with just a

Here's a straightforward implementation using a for loop and string indices: #

public class Main {
    public static void main(String[] args) {
        String original = "Jamaica";
        
        // Loop from index 0 to the last index of the string
        for (int i = 0; i < original.length(); i++) {
            // Grab the substring starting at index i to the end of the string
            String currentSubstring = original.substring(i);
            // Print the substring followed by a space
            System.out.print(currentSubstring + " ");
        }
    }
}

Let's break down what this code does: #

• Original String: We start by defining the base string "Jamaica".
• For Loop: The loop variable i starts at 0 (the first character's index in Java strings) and runs until it reaches the length of the string. Since "Jamaica" has 7 characters, i will take values 0 through 6 (7 total iterations, one for each substring we need).
• Substring Method: original.substring(i) returns a new string that starts at index i and includes all characters from that point to the end of the original string. For example:
  • When i=0, it returns "Jamaica"
  • When i=1, it returns "amaica"
  • ...
  • When i=6, it returns "a"
• Printing: Using System.out.print() instead of println() ensures all substrings are printed on the same line, with spaces between them.

Optional: Fix the trailing space #

If you want to avoid the extra space at the end of the output, you can adjust the loop to only print a space when it's not the last iteration:

public class Main {
    public static void main(String[] args) {
        String original = "Jamaica";
        
        for (int i = 0; i < original.length(); i++) {
            System.out.print(original.substring(i));
            // Only add a space if we're not on the last substring
            if (i != original.length() - 1) {
                System.out.print(" ");
            }
        }
    }
}

Key concepts to remember: #

• String Indices: Java strings are zero-indexed—meaning the first character is at index 0, the second at 1, and the last character is at original.length() - 1.
• substring() Method: This is a built-in string method that lets you extract parts of a string. The version we used (substring(int beginIndex)) takes the starting index and returns everything from that point onward.
• Loop Control: By incrementing i each iteration, we're effectively "chopping off" the first character of the original string each time, which gives us exactly the sequence you want.

内容的提问来源于stack exchange，提问作者coding anonymous