java - 我在方法中得到了正确的反转字符串，但是当我返回到 main() 时，它显示错误的字符串作为输出

Question

/*
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 * and open the template in the editor.
 */
package revstring;

/**
 *
 * @author Pawan
 */
public class RevString {

    private String substr="";
    private String temp="";
    private static int strLength=0;
    private String reversed="";

   public String revString(String str)
    {
        Character ch;

        strLength=str.length();
        System.out.println("length- "+strLength);

        if(strLength!=0)
        { 
            ch=str.charAt(strLength-1);          
            temp=temp+ch;                        
            substr=str.substring(0,strLength-1); 
            if(substr.equals("")){reversed=temp; return reversed;}
            return temp+revString(substr);  
        }
        return reversed;         
    }


    public static void main(String[] args) {
       RevString rev=new RevString();
       System.out.println("reversed string- "+rev.revString("PAWAN"));
    }


}

Answer 1

您的问题是您将变量用作类变量，即 substr、temp、strLength、reversed 应该在 revString() 中。然后就可以了。

固定:

public class RevString {


public String revString(String str) {
    String substr="";
    String temp="";
    int strLength=0;
    String reversed="";
    Character ch;
    strLength=str.length();
    System.out.println("length- "+strLength);

    if(strLength!=0)
    { 
        ch=str.charAt(strLength-1);          
        temp=temp+ch;                        
        substr=str.substring(0,strLength-1); 
        if(substr.equals("")){reversed=temp; return reversed;}
        return temp+revString(substr);  
    }
    return reversed;         
}


public static void main(String[] args) {
   RevString rev=new RevString();
   System.out.println("reversed string- "+rev.revString("PAWAN"));
}

}