check « character « Java Data Type Q&A

1. How can I check if a single character appears in a string?

In Java is there a way to check the condition: "Does this single character appear at all in string x" without using a loop? Thank you,

2. How to check if a Java character is a currency symbol

I have to perform a check on a character variable to see whether or not it is a currency symbol. I have discovered the Character.UnicodeBlock.CURRENCY_SYMBOLS constant however I am unsure of ...

3. Best coding Style - Checking if a character is a valid character

I am coding a method that returns whether a given character is valid, which looks like this: -

private static boolean isValid(char c) {
    return c == '.' || ...

4. JAVA: check a string if there is a special character in it

How do you check a string if there is a special character like: [,],{,},{,),*,|,:,>,etc.?

5. Java: Checking contents of char variable with if condition

I have a char variable that is supposed to contain either a Y,y,n or N character, I want to test if it does not contain it, then display an error message ...

6. How to check if a string contains two asterisk characters?

We have a string input and the following combinations are valid (e.g. sunday, *sunday*, sun*day*, *sun*day, su*nda*y) If it contains only a single asterisk, then it is a bad input. So given the ...

7. character checking

if (c=='a' || c=='e' || c=='i' || c=='o' || c=='u') { count++; When i give the above statement it returns number of vowels in a ...

8. Checking if 2 strings contain the same characters?

Is there a way to check if two strings contain the same characters. For example,

abc, bca -> true
aaa, aaa -> true
aab, bba -> false
abc, def -> false

9. How to check if only chosen characters are in a string?

What's the best and easiest way to check if a string only contains the following characters:

I want like an example like this pseudo-code:
//If String contains other characters
//if string contains only those ...

10. How to check if a char is equal to an empty space?

Here's what I've got:

private static int countNumChars(String s) {
    for(char c : s.toCharArray()){
        if (Equals(c," "))
But that ...

11. how to check if a character is equal to double quote in java

I want to check the value of a char to see if it is double quote or not in Java. How can I do it?

12. Simple way to determine if string is only characters, or to check if string contains any numbers in Java

I have to read in a name for a string, and then verify that it is a name. So something like"smith23" would have to be used to abort the program. ...

13. How to check for a single character and break a loop

I have this loop:

String cont = "";
while ( cont != "n" ) {
// Loop stuff

System.out.print("another item (y/n)?");
cont =;
However, when I type "n" to stop the loop, it just keeps running. ...

14. checking for is letter in a string

I am asking for user input in a string and i want to check for is alpha or numeric but i am new to java. this is what i have so ...

15. checking a String for anything other than an integar or character a - z

This is dealing with java to start. My goal is to take in a Vin number and store it into a string. Make sure it has no more than 9 characters. ...

16. how to check a string for a special character in Java

Possible Duplicate:
JAVA: check a string if there is a special character in it
I'm testing a method that transforms a string into another string except ...

17. Checking each character for a number

I am trying to loop through a string and check each character if one of the characters is a number. If it is a number, I want to return it as ...

18. How do I check for non-word characters within a single word in Java?

I want to know if a String such as "equi-distant" or "they're" contains a non-word character. Is there a simple way to check for it?

19. How do I check chars in a string for predetermined criteria?

I am so sorry for not getting back to you. Immediately after posting my question, my computers all died, so I was running around...again...figuring out a way to do my schoolwork, ...

21. best way to check whether a character is uppercase?

Offhand, I can't think of anything clever. But you can always go char by char... class StringBreaker { static String breakIt(String input) { StringBuffer buff = new StringBuffer(); for(int x = 0; x < input.length(); x++) { char c = input.charAt(x); if(Character.isUpperCase(c)) { buff.append(" " + Character.toLowerCase(c)); } else { buff.append(c); } } return buff.toString(); } public static void main(String[] args) ...

22. Check the Characters in Text Box!

This example just show you how to control the user input, user can type in 0-9 in the text field only: public void keyTyped( KeyEvent e) { char ch = e.getKeyChar(); System.out.println("key name: " + ch); if ( ch < '0' | | ch > '9' ) // not a digit e.consume(); } Hope this helps! You need to register your ...

24. Character checking

Hi, Welcome to JavaRanch! Well, as I see it, there are a number of steps here: 1) Getting ahold of the String in question; 2) Checking that it's 9 characters long; 3) Getting ahold of the String's 1st character; 4) Checking that it's uppercase; and 5) Reporting the result of the tests. Let us know which of these parts you're having ...

25. checking a string for illegal required....

Hello. I am trying to make my program read a token from a string, and print out an error if the token contains invalid characters, ie smit4h. I have this.... public static void surnameValidation()// surname validation { for(int i=0; i

27. How do i check for special characters

28. check variable.nextDouble() is a number not characters

I am doing a program that should act as a calculator; I have the following in it now how do I check if the value of x is an integer and NOT some random character. I hope I am being clear thanks // initialize first input1 number Scanner input1 = new Scanner(; // prompt for the first number System.out.println("Please enter the ...

29. Checking for java special characters in a string

Hi i want to check whether there is any java special character exist in a string or not. Could anybody help me on this. Special Characters: \!@#$%^*()_+|}{[]\:';"<>,./? ...

30. How to check whether the string contains only the specified characters?

Hi, I may get more than 1000 lines in a file. Each line ends with a new line character. Sometimes the file may have 4 lines. Other lines will have characters such as , : alone. I'm storing each line in the database if it is a valid line and If the line contains only the above characters (, : ) ...

31. How to check whether the string contains only the specified characters ????

Hi, I may get more than 1000 lines in a file. Each line ends with a new line character. Sometimes the file may have 4 lines. Other lines will have characters such as , : alone. I'm storing each line in the database if it is a valid line and If the line contains only the above characters (, : ) ...

32. check a string char by char

check a string char by char Hi, first of all the code: Java Code: import*; import java.util.Calendar; import java.text.SimpleDateFormat; import java.text.DecimalFormat; class UserInput { public static String getString() { String line; InputStreamReader input=new InputStreamReader(; BufferedReader in=new BufferedReader(input); try { line=in.readLine(); return line; } catch(Exception e) { return "Exception"; } } public static int getInteger() { String line; InputStreamReader ...

33. Coding question to check if string contains some chars?

Hello I have below program in this program I want to check if string a contains all char in char[] b array, with the example of String a="cash" and char[] b={'c', 'h'}, I have correct result, unfortunately my string and char array will be dynamic, will change during the program and if I have String a="h" and char[] b={'c', 'h'}, my ...

35. check a char variable if empty

Hello, How can I check if a variable is empty or not? I have a JTextField and if the user didn't type anything in, I want the JLabel to turn red. The if statement I'm using doesn't work: if (tailnumber == "") I'm not familiar with the Java operators... can you use !tailnumber ? I know this is a simple question, ...

36. check a string for certain characters

38. Checking char differences between 2 strings

hsc71 wrote: Take the length of the shortest string. The difference in length is an error anyway according to what youv'e written. No, based on what he's said so far, he'll at least need to take the difference in the lengths, and probably add to it the number of differences in corresponding characters along the shared length. Like I said though, ...

39. how to check if a 'char' (character) is lower cased or uppercased? How To Ask Questions The Smart Way Eric Steven Raymond Rick Moen Write in clear, grammatical, correctly-spelled language We've found by experience that people who are careless and sloppy writers are usually also careless and sloppy at thinking and coding (often enough to bet on, anyway). Answering questions for careless and sloppy thinkers is not rewarding; we'd rather spend our ...

40. how to check if String contains a given char?

41. Check bit in char, problem from a contest?

42. How could i check if a String contains only specified characters?

Nope, I got this example from web. I worked this out sucessfully. Now i know how to check using matcher and pattern in java , if i have a regex. What i need is to check if a string contains only this charaters. abcdefghijklmnopqrstuvwxyz-.@_ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789 i could not create a valid regex to do the same. I need help here.

43. How to check whether the string contains only the specified characters ????

Hi, I may get more than 1000 lines in a file. Each line ends with a new line character. Sometimes the file may have 4 lines. Other lines will have characters such as , : + alone. I'm storing each line in the database if it is a valid line and If the line contains only the above characters (, : ...

44. Printable ASCII character Check

/** * @param inputStr * @return boolean: true of valid string * @desc Check for special characters string */ public static boolean isValidPassword(String inputStr) { boolean isValidStr = true; for (int i= 0; i < inputStr.length(); i++) { char ch= inputStr.charAt(i); if (!isAlphaNumeric(ch+"")) { // Special Character // Domain Value Check if (!(isValidSpecialCharacter(ch))) { isValidStr = false; break; } } } ...

45. Checking for other characters than a-z and accented characters

Hi, I'd like to know if there's an easy way to check if a character in a string isn't a standard a-z character (not a number or punctuation or special characters). I want special characters like and to be treated as a letter, meaning not returning the method true. Please help, Considerate

46. Trying to check if the next character is a number.... NEED HELP!!

Of course there is more code but this is the basic part that I am having trouble. I haven't even been able to successfully run it. The part that is giving me the ttrouble is in bold. I have tried everything that I know how to... If someone could help me then that would be great. I have already done a ...

50. checking if a character is empty...

HI. I am writing some validation code, and basically need to check whether the user pressed the enter key when they were asked to enter input (which is saved into a character variable).... how would i go about doing this? I know how to do it with a string as i check if the string is equals "" but I dont ...

51. How to check if char is null

Would like to know how-to check if a char typed value is null. public class MyHelper { public int Number; public static char computeCh() { char ch; // Implementation to compute ch. return (ch); } } // Inside Calling method. if ( MyHelper.computeCh() != null) // it does throw compilation error. { // Code goes on...... }

52. How can we check if a char value is null

53. Doing a character check on a word?

55. checking if string contains same chars

Hi I am new to java, but have some trouble with it. What is the easiest way to check if the specific string contains same characters and if so, then printing it out? For example, if the string is "abcd", then the program prints nothing, but if the string is "abcab", then it prints "yes a, yes b". It should be ...

56. Checking String for unwanted characters

Can anyone think of, or know of, a way of checking a String for odd characters? For example, someone has produced an XML document using MS Word, and it contains some of those word-specific characters that would break an xml parser. I've tried using the Regex package, but that gets too complex and you can't include all the characters I want ...

57. How do I throw an exception to check a character in a string?

How do I throw an exception to check a character in a string? I'm trying to create an if statement where it can check in a string for certain characters. And when the character statements are met an exception has to be thrown. So far I've had no luck creating the if statement. Can someone help me out?

58. how to check special character

If I use following code It is printing all special characters as a ? so it's ASCII value is 63, so I can't able to relay on this 63 value, bcz here in my String there is one "?" character is there but How do I know whether it is a "?" or some other character. String a = "Ab^)]%$#@!?><:;\"'}{"; final ...