String charAt() method returns a particular Character at the specified index in the String.
How is this function implemented internally?. How a particular character can be retrieved from String?.
I'm trying to use the split method to split a string for a calculator, but it keeps throwing this Exception:
Exception in thread "main" java.util.regex.PatternSyntaxException: Dangling meta character '+' near index 0
+
public class exp {
private static String ques="88+12";
private static String [] splitCalc;
public static void main(String[] args) {
splitCalc = ques.split("+");
for(String s : splitCalc){
System.out.println(s);
}
}
}
I am trying to remove a character from string as below
public String reomveChar(String str, int n) {
if(0<=n & n<=(str.length()-1)){
//str.charAt(n)
char o=str.charAt(n);
return str.replace("o","");
//a.replace("o","");
}
return null;
}'
what is the best way to remove it.
If i call like
removeChar("hello", 1) i should see hllo.
When there are more than one way to do a challenge in java which one to choose as best way.
What is the criteria to decide one particular way of writing code is best among say 'n' different number of ways.
I am trying to swap given string first and last character. If I pass world i should get 'dorlw'
I found link and code [URL]....
String str="hello";
char[] charArray=str.toCharArray();
int indexOfLastChar=charArray.length-1;
for(int i=0;i<charArray.length/2;i++){
char temp=chatArray[i];
charArray[1]=charArray[indexOfLastChar-i];
charArray[indexOfLastChar-i]=temp;
}
String reversedStr=new String(charArray)
System.out.println("reversed string"+str+reversedStr);
I wonder Is there is any easy simple way to do it.
so my task is to write a code which would ask user to input the year as integer and first three letters of the month with first being an upper case letter. Than the program would determine the number of days for given year and month.
Currently I have a brain crash on how to check, if the user has provided the month with first character being upper Case. If not, than the program would automatically correct the character. Problem starts at line 17.
import java.util.Scanner;
public class DaysOfMonth4_17 {
public static void main (String[] args) {
//Initiate scanner
Scanner input = new Scanner (System.in);
//Ask for year input and use is as INT
System.out.println("Enter the year");
[code]...
the number of occurrences of a specified character in a string...i tried to do the program occurrences in a given string and i tried the code as below.
code:
import java.util.*;
public class Occurrence
{
public static void main(String[] args)
{
Scanner input = new Scanner(System.in);
[code]....
I have to create a code that can calculate the number of upper case letters in a string that is entered by the user (below.)
Java Code:
import javax.swing.JOptionPane;
public class mainClass {
public static void main (String [] args) {
String userInput;
userInput = JOptionPane.showInputDialog("Enter a string.");
[Code] ....
My issue is that I would like the program to be able to function properly when spaces are entered into the string. As it is right now, I believe it is only processing the first string entered into the input box.
How I can convert a string into a character array without using toCharArray???
View Replies View RelatedWhich string method to search a particular character in a string whether a particular character is there or not . Suppose my String is like............
String s = "Java.";
How I can find the character " . " in above string "Java." is present or not . What is the string method to search that "."
What should be the code if i want to input a different string in case of the typed string. The case is : I have a predefined string S = "Peter,please answer my question" and now when i input another string inside the text field character by character i want characters from the string S to enter instead of the input string. In short, the input string should be disguised as string S.
View Replies View RelatedNow I am doing dictionary app using files..
Here i want to print the String from Starting character which is given by user..Here i given below the image like my concept..here we put .(dot and enter R)eclipse will print the method name which is starting from R..
import javax.swing.*;
public class mostFrequent{
public static void main(String args[]){
char index;
String s;
s = JOptionPane.showInputDialog("Enter String here");
int currFrequency = 0;
for(index = 0; index<s.length(); index = index++){
int i = 0;
for(i = 'A'; i<='Z'; i++){
if(i==s.charAt(index)){
currFrequency = currFrequency + 1;
}
}
}
System.out.println("end");
}
}
//my code so far
I have to write some code to take names from the user and then order them in alphabetical order and then print them out which i have managed to do. However, i can't get it to count the characters in the names that the user enters or count the amount of vowels in the names.
This is the code ive written:
import javax.swing.JOptionPane;
import java.util.Arrays;
String[] names = new String[9];
int i;
names[0] = JOptionPane.showInputDialog("Please enter a name");
names[1] = JOptionPane.showInputDialog("Please enter a name");
[code]....
I have this program to see the occurrences of a character in a string stored in a text file. My text file has the following contents (as shown below):
P-P-N-N-L-V
N-R-U-S-R-Q
K-Q-E-L-E-A
A-J-B-G-E-F
F-E-L-Q-R-R
U-F-J-V-I-M
P-I-Q-K-B-K
U-N-L-F-O-B
M-A-N-M-H-O
P-Q-J-D-N-I
G-U-O-D-F-I
Q-M-M-B-C-Q
N-B-I-L-E-J
S-A-T-Q-H-U
C-L-G-U-J-M
R-P-V-M-A-A
C-R-A-V-L-B
M-U-Q-K-M-Q
E-I-C-H-V-J
J-N-N-K-R-P
As you notice, each character is seperated by a hyphen (serving as its delimiter). I want to only go through 10 lines in the text, instead of all 20 of them. So, I wrote the program in such a way that I intend to reach into the indices of each character in the text file. Since there are six characters in each line so that means there are 6 indices - and there are 10 lines I only want to go through. So, 6 indices times 10 lines equals 60 indices. Hence, there are only 60 indices I need to go through. In that manner, it's like I have gone through only 10 lines through that way.
It compiled perfectly fine but upon running it, I ran through an error in the black DOS screen that says
"java.lang.ArrayIndexOutofBoundsException: 6 ".
How do I work around that?
The code I wrote is shown below...
import java.io.*;
import java.util.*;
public class hotandcoldclusterdeterminer_test {
public static void main (String args [])throws IOException {
[Code]....
The String class stores the characters of the string internally as a private char[] and calling someString.length() results in getting the length field from the character array. I am looking to get the details on how the length is implemented. I understand it is a field, but in the original question I provide sample code and really want to know if/how the resulting byte code may differ when compiled, perhaps I am just not seeing the simple answer through my confusion.
Link ....
I have to validate a string whether it is a combination lowercase and uppercase and has the character '_'.
I m having trouble in framing the expression for these conditions in the matches function.
How it can be done..?? How to frame a the correct expression.
I have this program to see the occurrences of a character in a string stored in a text file. My text file has the following contents (as shown below):
Quote
P-P-N-N-L-V
N-R-U-S-R-Q
K-Q-E-L-E-A
A-J-B-G-E-F
F-E-L-Q-R-R
U-F-J-V-I-M
P-I-Q-K-B-K
U-N-L-F-O-B
M-A-N-M-H-O
P-Q-J-D-N-I
G-U-O-D-F-I
Q-M-M-B-C-Q
N-B-I-L-E-J
S-A-T-Q-H-U
C-L-G-U-J-M
R-P-V-M-A-A
C-R-A-V-L-B
M-U-Q-K-M-Q
E-I-C-H-V-J
J-N-N-K-R-P
Write a program using a while-loop (and a for-loop) that asks the user to enter a string, and then asks the user to enter a character. The program should count and display the number of times that the specified character appears in the string. (So, you will have two separate program codes, one using a while-loop and the other one using a for-loop.)
Example:
Enter a string: "Hello, JAVA is my favorite programming language."
Enter a character: e
The number of times the specified character appears in the string: 3
I don't even know where to begin I've only got this
import java.util.Scanner;
public class letterCounter {
public static void main(String [] args) {
Scanner sc = new Scanner(System.in);
System.out.println("Enter a string");
String myString = sc.nextLine();
System.out.println("Enter a letter");
String letter = sc.nextLine();
}
}
I wrote a program to read a .txt file and return how many times a, e, s, and t occur in the .txt file. I am getting an error that I do not know how to fix. It says Error: FileNotFoundException cannot be resolved to a type...
import java.util.Scanner;
import java.io.File;
import java.io.IOException;
import java.io.BufferedReader;
public class Count
{
public static void main (String[] args) throws FileNotFoundException {
String phrase; // a string of characters
[Code] ....
i want to have a JLabel that could "robotically" type words character by character.
View Replies View RelatedI use Eclipse (kepler version, with JDK 7) on MacBook Pro (Lion).I want to overwrite a line printed on my console. I used "" for that. I was expecting the cursor to go to the beginning of the line. Instead, it is going to the next line.
Code:
System.out.print("Superman
Sober");
Expected Output:
Soberman
Actual Output:
----------------
Superman
Sober
What I am trying is find the XOR value between charcters of a String here is my code
public static void main(String[] args) {
System.out.println(grayCode("100"));
}
public static String grayCode(String input){
StringBuilder temp=new StringBuilder();
temp.append(input.charAt(0));
for(int j=1;j<input.length();j++){
char previous=input.charAt(j-1);
char current=input.charAt(j);
char xorVal=(char)(previous^current);
temp.append(xorVal);
}
return temp.toString();
}
but I am not getting actual XOR value of two charcters that I am trying to get.
I am trying to build up the alphabet character by character. Like:
a
ab
abc
abcd
Well as of now I can only print out the alphabet with my loop like abcdefg...z.. So here is the code I am trying to use:
public void loop4() {
char alph = 'a';
while(alph <= 'z') {
System.out.println(alph);
alph++;
}
}
I have entered more than one character but output is only one character .....
class InputUser
{
public static void main(String arg[])
throws java.io.IOException
{
char ch;
ch=(char) System.in.read();
System.out.println(ch);
}
}
If my xml file (shown below as sample) has different employees with id's - is there a way I can get just the id's on there own?
Java Code:
<Employees>
<Employee id="1">
<age>29</age>
<name>Pankaj</name>
<gender>Male</gender>
<role>Java Developer</role>
</Employee>
<Employee id="2">
<age>35</age>
<name>Lisa</name>
<gender>Female</gender>
<role>CEO</role>
</Employee>
</Employees> mh_sh_highlight_all('java');
This is the code Im using - I know at the minute it gets the id details of id 3 but realistically I just want the id's and nothing else
Java Code:
private static String getEmployeeById(Document doc, XPath xpath, int id) {
String env = null;
try {
XPathExpression pathExpression =
xpath.compile("/Employees/Employee[@id=3]"); // line gets everything to do with id 3 but doesn't display the id
[code]....
Can this be achieved using xpath? I've been stuck on it for ages and I can't seem to really find anything to do with it
I need to retrieve an image from the MySQL DB and display it in my JSP. The code below retrieves and displays the image with success. But, an exception is thrown:
SEVERE: Servlet.service() for servlet [jsp] in context with path [/FileFinalText] threw exception
[java.lang.IllegalStateException: getOutputStream() has already been called for this response] with root cause
java.lang.IllegalStateException: getOutputStream() has already been called for this response
[code]...
how can I resolve the cause with the getOutputStream() and prevent this exception to occur?