Java 字符串赋值不';不行?
在我的最后一个else-if语句(在程序末尾)中,我打印出了两个变量(CodeCheck和cPass),我想签入下面的if-else语句。包括其长度在内,这些值都是正确的。但是,它没有进入if语句(cPass==“Skyfall”),这意味着它将其视为false。如果我在If-else语句开始工作之前分配字符串(即cPass=“Skyfall”)(它会将其视为true) 我不明白为什么,在if-else语句中,以下内容似乎不起作用:Java 字符串赋值不';不行?,java,Java,在我的最后一个else-if语句(在程序末尾)中,我打印出了两个变量(CodeCheck和cPass),我想签入下面的if-else语句。包括其长度在内,这些值都是正确的。但是,它没有进入if语句(cPass==“Skyfall”),这意味着它将其视为false。如果我在If-else语句开始工作之前分配字符串(即cPass=“Skyfall”)(它会将其视为true) 我不明白为什么,在if-else语句中,以下内容似乎不起作用: cPass = String.format("%s",e.ge
cPass = String.format("%s",e.getActionCommand());
同样地:
CodeCheck = String.format("%d%d%d", cCode[0], cCode[1], cCode[2]);
但是,它可以打印这些变量的值(及其长度)
以下是该程序的所有代码:
import java.awt.FlowLayout;
import javax.swing.JFrame;
import javax.swing.JButton;
import javax.swing.JOptionPane;
import javax.swing.JPasswordField;
import javax.swing.JTextField;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import javax.swing.Icon;
import javax.swing.ImageIcon;
public class SecurityWindow extends JFrame{
JButton n1 = new JButton("1");
JButton n2 = new JButton("2");
JButton n3 = new JButton("3");
JButton n4 = new JButton("4");
JButton n5 = new JButton("5");
JButton n6 = new JButton("6");
JButton n7 = new JButton("7");
JButton n8 = new JButton("8");
JButton n9 = new JButton("9");
JTextField username = new JTextField("username");
JPasswordField password = new JPasswordField("password");
JButton play;
public SecurityWindow(){
super("Security Passage");
setLayout(new FlowLayout());
add(username);
add(password);
add(n1);
add(n2);
add(n3);
add(n4);
add(n5);
add(n6);
add(n7);
add(n8);
add(n9);
Icon dec = new ImageIcon(getClass().getResource("faceb.png"));
play = new JButton("Login", dec);
add(play);
HandlerClass handler = new HandlerClass();
username.addActionListener(handler);
password.addActionListener(handler);
n1.addActionListener(handler);
n2.addActionListener(handler);
n3.addActionListener(handler);
n4.addActionListener(handler);
n5.addActionListener(handler);
n6.addActionListener(handler);
n7.addActionListener(handler);
n8.addActionListener(handler);
n9.addActionListener(handler);
play.addActionListener(handler);
}
int cCode[] = {10,10,10};
String cUser = "";
String cPass = "";
String CodeCheck = "";
private class HandlerClass implements ActionListener{
public void actionPerformed(ActionEvent e){
if(e.getSource() == username){
cUser = String.format("%s",e.getActionCommand());
}else if(e.getSource() == password){
cPass = String.format("%s",e.getActionCommand());
}else if(e.getSource() == n1){
if(cCode[0] == 10){
cCode[0] = Integer.parseInt(e.getActionCommand());
}else if(cCode[1] == 10){
cCode[1] = Integer.parseInt(e.getActionCommand());
}else if(cCode[2] == 10){
cCode[2] = Integer.parseInt(e.getActionCommand());
}
}else if(e.getSource() == n2){
if(cCode[0] == 10){
cCode[0] = Integer.parseInt(e.getActionCommand());
System.out.println(cCode[0]);
}else if(cCode[1] == 10){
cCode[1] = Integer.parseInt(e.getActionCommand());
}else if(cCode[2] == 10){
cCode[2] = Integer.parseInt(e.getActionCommand());
}
}else if(e.getSource() == n3){
if(cCode[0] == 10){
cCode[0] = Integer.parseInt(e.getActionCommand());
}else if(cCode[1] == 10){
cCode[1] = Integer.parseInt(e.getActionCommand());
}else if(cCode[2] == 10){
cCode[2] = Integer.parseInt(e.getActionCommand());
}
}else if(e.getSource() == n4){
if(cCode[0] == 10){
cCode[0] = Integer.parseInt(e.getActionCommand());
}else if(cCode[1] == 10){
cCode[1] = Integer.parseInt(e.getActionCommand());
}else if(cCode[2] == 10){
cCode[2] = Integer.parseInt(e.getActionCommand());
}
}else if(e.getSource() == n5){
if(cCode[0] == 10){
cCode[0] = Integer.parseInt(e.getActionCommand());
}else if(cCode[1] == 10){
cCode[1] = Integer.parseInt(e.getActionCommand());
}else if(cCode[2] == 10){
cCode[2] = Integer.parseInt(e.getActionCommand());
}
}else if(e.getSource() == n6){
if(cCode[0] == 10){
cCode[0] = Integer.parseInt(e.getActionCommand());
}else if(cCode[1] == 10){
cCode[1] = Integer.parseInt(e.getActionCommand());
}else if(cCode[2] == 10){
cCode[2] = Integer.parseInt(e.getActionCommand());
}
}else if(e.getSource() == n7){
if(cCode[0] == 10){
cCode[0] = Integer.parseInt(e.getActionCommand());
}else if(cCode[1] == 10){
cCode[1] = Integer.parseInt(e.getActionCommand());
}else if(cCode[2] == 10){
cCode[2] = Integer.parseInt(e.getActionCommand());
}
}else if(e.getSource() == n8){
if(cCode[0] == 10){
cCode[0] = Integer.parseInt(e.getActionCommand());
}else if(cCode[1] == 10){
cCode[1] = Integer.parseInt(e.getActionCommand());
}else if(cCode[2] == 10){
cCode[2] = Integer.parseInt(e.getActionCommand());
}
}else if(e.getSource() == n9){
if(cCode[0] == 10){
cCode[0] = Integer.parseInt(e.getActionCommand());
}else if(cCode[1] == 10){
cCode[1] = Integer.parseInt(e.getActionCommand());
}else if(cCode[2] == 10){
cCode[2] = Integer.parseInt(e.getActionCommand());
}
}else if(e.getSource() == play){
CodeCheck = String.format("%d%d%d", cCode[0], cCode[1], cCode[2]);
System.out.println(CodeCheck);
System.out.println(cPass);
if(cPass == "Skyfall"){
if(CodeCheck == "558"){
JOptionPane.showMessageDialog(null, cUser + ", you have cracked the security system");
}else{
System.out.println("cPass wrong");
}
}else{
JOptionPane.showMessageDialog(null, "No Access Granted " + cUser);
/*JOptionPane.showMessageDialog(null, CodeCheck);
JOptionPane.showMessageDialog(null, cPass);
JOptionPane.showMessageDialog(null, cUser);*/
System.out.println(CodeCheck);
System.out.println(cPass);
System.out.println(cUser);
System.out.println(cPass.length());
System.out.println(CodeCheck.length());
}
}
}
}
}
提前感谢。使用
equals()
方法进行字符串比较。使用=
运算符,可以比较两个字符串的内存地址。使用equals()
方法,可以比较两个字符串的值。所以不是
if(cPass==“Skyfall”)
使用
if(cPass.equals(“Skyfall”)
你为什么要发布所有不相关的代码?这样,如果必要的话,你可以查看并跟踪整个程序。在我看来,你好像还没有做过研究。感谢你的帮助,我不知道以前有人问过这个问题;)