Java 删除字符串的最后一个字符
[英]Deleting Last Character From a String in Java
问题描述
I'm writing a java code which gives an error when typing more than 10 characters in a PasswordField and cannot type from there on.
我正在编写一个 java 代码，当在 PasswordField 中输入超过 10 个字符时会出错，并且无法从那里输入。 I tried deleting the last character from the PasswordField on a KeyPressed event but instead of deleting the last character, it deletes the character before it and replace it with the last character.Here goes my code.我尝试从 KeyPressed 事件的 PasswordField 中删除最后一个字符，但不是删除最后一个字符，而是删除它之前的字符并将其替换为最后一个字符。这是我的代码。
private void passFieldKeyTyped(java.awt.event.KeyEvent evt) {私有无效passFieldKeyTyped（java.awt.event.KeyEvent evt）{
String pw1 = new String(passField.getPassword());
if(passField.getPassword().length==10){
try{
StringBuffer bf = new StringBuffer(pw1);
bf.deleteCharAt(10);
String pw2 = new String(bf);
passField.setText(pw2);
JOptionPane.showMessageDialog(this, "<html><h4>Password Must Not Contain More Than 10 Characters !</h4></html>", "Error !", JOptionPane.ERROR_MESSAGE);
}
catch(Exception e){
JOptionPane.showMessageDialog(this, e.getMessage());
}
}
I'm still a newbie for programming.我仍然是编程的新手。 I hope someone can help me with this.我希望有人能帮我解决这个问题。 Thanks !谢谢 ！
3 个解决方案
解决方案1
0 2020-09-12 07:35:15
public class RemoveChar {
public static void main(String[] args) {
String str = "India is my country";
System.out.println(charRemoveAt(str,));
}
public static String charRemoveAt(String str) {
return str.substring(0, str.length()-1);
}
}
解决方案2
0 已采纳 2020-09-12 07:43:13
I guess you are trying to delete a char from the String.我猜你正试图从字符串中删除一个字符。
You can use the StringBuilder class here to delete a character at your specified position.您可以在此处使用StringBuilder类删除指定位置的字符。 First convert your String to StringBuilder -首先将您的字符串转换为StringBuilder -
StringBuilder sb = new StringBuilder(inputString);
Then you can use the built in method deleteCharAt() to delete the char at your desired position like this -然后您可以使用内置方法deleteCharAt()删除您所需位置的字符，如下所示 -
sb.deleteCharAt(10);
Hope this may help you.希望这可以帮助你。
解决方案3
0 2020-09-12 07:59:25
Guys I'm so sorry I found out it was a mistake of mine..I actually had to check the length of the passwordfield again and length must be 11 to delete the 10th character.伙计们，我很抱歉我发现这是我的错误。实际上我不得不再次检查密码字段的长度，长度必须是 11 才能删除第 10 个字符。 Here goes the code.It worked..Thanks for helping guys !!!!!!!!这是代码。它有效..感谢您的帮助！！！！！！！！！
private void passFieldKeyTyped(java.awt.event.KeyEvent evt) {私有无效passFieldKeyTyped（java.awt.event.KeyEvent evt）{
String pw1 = new String(passField.getPassword());
if(passField.getPassword().length==11){
try{
StringBuffer bf = new StringBuffer(pw1);
bf.deleteCharAt(10);
String pw2 = new String(bf);
passField.setText(pw2);
JOptionPane.showMessageDialog(this, "<html><h4>Password Must Not Contain More Than 10 Characters !</h4></html>", "Error !", JOptionPane.ERROR_MESSAGE);
}
catch(Exception e){
JOptionPane.showMessageDialog(this, e.getMessage());
}
}
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