Java实现字符串倒序输出的几种方法

1. 最容易想到的估计就是利用String类的toCharArray()，再倒序输出数组的方法了。

import javax.swing.JOptionPane;  

public class ReverseString {  

    public static void main (String args[]){
        String originalString;
        String resultString = "";     

        originalString = JOptionPane.showInputDialog("Please input a String: ");  

        char[] charArray = originalString.toCharArray();  

        for (int i=charArray.length-1; i>=0; i--){
            resultString += charArray[i];
        }  

        JOptionPane.showMessageDialog(null, resultString, "Reverse String", JOptionPane.INFORMATION_MESSAGE);
    }
}

import javax.swing.JOptionPane;  

public class ReverseString {  

    public static void main (String args[]){
        String originalString;
        String resultString = "";     

        originalString = JOptionPane.showInputDialog("Please input a String: ");  

        char[] charArray = originalString.toCharArray();  

        for (int i=charArray.length-1; i>=0; i--){
            resultString += charArray[i];
        }  

        JOptionPane.showMessageDialog(null, resultString, "Reverse String", JOptionPane.INFORMATION_MESSAGE);
    }
}

2. 还可以利用String类提供的subString()方法，利用递归的办法输出倒序字符串。

import javax.swing.JOptionPane;  

public class ReverseString {
    public static void reverseString (String str){
        if (str.length() == 1){
            System.out.print(str);
        }
        else{
            String subString1 = str.substring(0, str.length()-1);
            String subString2 = str.substring(str.length()-1);  

            System.out.print(subString2);  

            reverseString (subString1);
        }
    }  

    public static void main (String args[]){
        String originalString;  

        originalString = JOptionPane.showInputDialog("Please input a String: ");  

        reverseString (originalString);
    }
} 

import javax.swing.JOptionPane;  

public class ReverseString {
    public static void reverseString (String str){
        if (str.length() == 1){
            System.out.print(str);
        }
        else{
            String subString1 = str.substring(0, str.length()-1);
            String subString2 = str.substring(str.length()-1);  

            System.out.print(subString2);  

            reverseString (subString1);
        }
    }  

    public static void main (String args[]){
        String originalString;  

        originalString = JOptionPane.showInputDialog("Please input a String: ");  

        reverseString (originalString);
    }
} 

3. 还有就是不把字符串定义为String类，而是定义成一个StringBuffer类，用StringBuffer类中的reverse()方法直接倒序字符串。

    import javax.swing.JOptionPane;  

    public class ReverseString {
        public static void reverseString (String str){
            StringBuffer stringBuffer = new StringBuffer (str);  

            System.out.print(stringBuffer.reverse());
        }  

        public static void main (String args[]){
            String originalString;  

            originalString = JOptionPane.showInputDialog("Please input a String: ");  

            reverseString (originalString);
        }
    }