first of all I want to say that I am kinda new to Java. So please be easy on me :)
I made this code, but I cannot find a way to change a character at a certain substring in my progress bar. What I want to do is this:
My progressbar is made out of 62 characters (including |). I want the 50th character to be changed into the letter B (uppercase).It should look something like this: |#########----B--|
I tried several things, but I dont know where to put the line of code to make this work. I tried using the substring and the replace code, but I can't find a way to make this work. Maybe I need to write my code in a different way to make this work? I hope someone can help me.
Thanks in advance!
int ecttotal = ectcourse1+ectcourse2+ectcourse3+ectcourse4+ectcourse5+ectcourse6+ectcourse7;
int ectmax = 60;
int ectavg = ectmax - ecttotal;
//Progressbar
int MAX_ROWS = 1;
for (int row = 1; row == MAX_ROWS; row++)
{
System.out.print("|");
for (int hash = 1; hash <= ecttotal; hash++)
System.out.print ("#");
for (int hyphen = 1; hyphen <= ectavg; hyphen++)
System.out.print ("-");
System.out.print("|");
}
System.out.println("");
System.out.println("");
}
Can you tell a little more what you want. Because what i sea it that, that you write some string into console. And is not way to change that what you already print to console.
Substring you can use only at String varibles.
If you want to change lettir with substring method in string varible try smth. like this:
String a="thi is long string try it";
if(a.length()>50){
a=a.substring(0,49)+"B"+a.substring(51);
}
Other way to change charater in string is to use string builder like this:
StringBuilder a= new StringBuilder("thi is long string try it");
a.setCharAt(50, 'B');
Sure you must first check the length of string to avoid the exceptions.
I hope that I helped you :)
Java StringBuilder has method setCharAt which can replace character at position with new character.
StringBuilder myName = new StringBuilder(<original string>);
myName.setCharAt(<position>, <character to replace>);
<position> starts with index 0
In your case:
StringBuilder myName = new StringBuilder("big longgggg string");
myName.setCharAt(50, 'B');
You can replace a certain index in a string by concatenating a new string around the intended index. For example the following code replaces the letter c with the letter X. Where 2 is the intended index to replace.
In other words, this code replaces the 3rd character in the string.
String s = "abcde";
s = s.substring(0, 2) + "X" + s.substring(3);
System.out.println(s);
Related
I want to reverse a string. I know there are some other methods to do it but I wanted to do in a different way. There is no error but no output when I run my code. I dont understand why "String.valueOf(word.charAt(i)" doesnt return a value? Am I missing something?
String word = "myword";
for (int i = word.length(); i <= 0; i--) {
System.out.print(String.valueOf(word.charAt(i)));
}
The first value of i is out of index. And I also fixed your code. Check below:
String word = "myword";
for(int i=word.length()-1;i>=0;i--){
System.out.print(String.valueOf(word.charAt(i)));}
Just for providing another slightly different solution:
You can use a StringBuilder to reverse a String using its method reverse().
If you have a String, you can use it to initialize the StringBuilder with it and directly reverse it.
This example additionally uses an enhanced for-loop, which always goes through all of the elements. Using that, you can get rid of checking the length of a String and you won't have to use an int i for iterating.
For your requirements, this is a suitable option because you want to reverse the whole String.
String word = "myword";
for (char c : new StringBuilder(word).reverse().toString().toCharArray()) {
System.out.println(c);
}
Note that you can use the reverse() method for printing the reversed word in one line just doing
System.out.println(new StringBuilder(word).reverse().toString());
Your code has 2 issues.
i should be initialized with word.length()-1. Other wise you will get StringIndexOutOfBoundsException
for loop condition should be >= 0.
Below is the corrected code.
String word = "myword";
for(int i=word.length()-1;i>=0;i--) {
System.out.print(word.charAt(i));
}
I tried to run this code and remove all uppercase characters and print the changed string again. But all it does is throwing me a "cannot find symbol - method delete(int,int)" error in the String function. I'm pretty sure the loop variable is visible too.
String s = "Some Random Sentence Here";
int l = s.length()
for(int i = 0;i<l;i++)
{
char ch = s.charAt(i);
if(Character.isUpperCase(ch) == true)
{
s.delete(i,(i+2));
}
}
System.out.println(s);
Edit: Thanks Mentallurg, forgot the i less than l part
As stated in the comments there is no deletefunction for a string. String behaves a bit like a primitive type in Java but in the end not really.
Anyways you can solve the problem easy with streams as shown here:
String s1 = "Some Random Sentence Here";
s1=Arrays.stream(s1.split("")).map(x->(x.equals(x.toUpperCase())&&!x.equals(" "))?"":x).collect(Collectors.joining());
System.out.println(s1);
The problem is forgotten minus l when you remove this character :D
Use StringBuffer instead of String.
Use
i < l
Or
i <= l-1
Because the indexing starts with 0 and the the last element has index l-1.
I'd like to count the amount of characters within a string, and cut off any excess characters of the string. I thought of just using a while loop and a char, but I need to pass in a string. I also tried to use the remainder function, but I"m pretty sure it wouldn't work.
So, essentially, a counter for a string and then to limit that string to x amount of characters.
If I were to set the string to a single character, say
String x = "*";
Then implemented a counter in a for loop...
for(int i = 0; i < 6; i++){
???
}
Would that work? I feel like it wouldn't, and that it would just be more effective for me to declare
char x = 'a';
...
I'm trying to make this as vague as possible so that I can take ideas and implement them so it's not like I'm stealing anybody's code for homework, I just need a little help.
String myString = "myString";
int maxLength = 3;
if (myString.length() > maxLength)
myString = myString.substring(0, maxLength);
Result will be "myS"
"I was searching around on the web for a manual code to count the amount of characters within a string, and then to a further extent cut off any excess characters of the string."
Count amount of characters within a string:
int length = stringName.length();
Cutting off extra characters of the string
int maxAmount; //wherever you want to stop
if(length > maxAmount)
{
stringName = stringName.substring(0,stopPoint);
}
So I have to tokenize a string, and I can only use these 2 methods to tokenize
I have the base, but I don't know what to put in,
My friend did it, but I forgot how it looked, it went something like this
I remember he split it using the length of a tab
public class Tester
{
private static StringBuffer sb = new StringBuffer ("The cat in the hat");
public static void main(String[] args)
{
for(int i = 0; i < sb.length() ; i++)
{
int tempIndex = sb.indexOf(" ", 0);
sb.substring(0,tempIndex);
if(tempIndex > 0)
{
System.out.println(sb.substring(0,tempIndex));
sb.delete(0, sb.length());
}
}
}
}
String.indexOf(int ch) returns the index of a character. If you do sb.indexOf(' ') you'll get the first index of a space. You can use that in conjunction with substring(): sb.substring(0,sb.indexOf(' ')-1) will get you your first token.
This seems like a homework problem, so I don't want to give you the full answer, but you probably can work it out. Comment if you need more help.
If your are familiar with a while loop construct you can take a look at my pseudocode, should be within the constraints of your problem:
String text = "texty text text"
while(TextHasASapce){
print text up to space
set text to equal all text AFTER the space
}
print ??
Using your two allowed methods the above is convertible line by line to what you are after.
Hope it helps.
I have to do this for an assignment in my java class. I have been searching for a while now, but only find solutions with regex etc.
For my assignment however I may only use charAt(), length() and/or toCharArray(). I need to get from a string like gu578si300 for example just the numbers so it will become: 578300.
i know numbers are 48 - 57 in ASCII but i can't figure out how to do this in java. You guys any ideas?
i was thinking about a for loop that checks whether the (int) char is between 48-57 en if so puts the value into a seperate array. Howeevr i dont know how to programm that last thing.
I now have this;
public static String filterGetallenreeks(String reeks){
String temp = "";
for (char c : reeks.toCharArray()) {
if ((int) c > 47 && (int) c < 58)
temp += c;
}
return temp;
however it is not working, it just outputs the same as goes in.
is it something in my mainm which looks like this. If i'm right the return temp; will return the temp string into the reeks string in the main right? why is my input still the same a sthe output?
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
System.out.println("Voer een zin, woord of cijferreeks in:");
String reeks = sc.nextLine();
if (isGetallenreeks(reeks)){
System.out.println("is getallenreeks");
filterGetallenreeks(reeks);
System.out.println(reeks);
}
Since this is homework I will not be providing the complete solution, however, this is how you should go about it:
Do a for loop that iterates for the total amount of characters within the string (.length). Check if the character is a digit using the charAt and isDigit methods.
You could do a loop that checks a character in the string, and if it's a number, append it to another string:
//I haven't tested this, so you know.
String test = "gu578si300 ";
String numbers = "";
for(int i=0; i<test.length(); i++){
if("0123456789".indexOf(test.charAt(i)) // if the character at position i is a number,
numbers = numbers + test.charAt(i); // Add it to the end of "numbers".
}
int final = Integer.parseInt(numbers); // If you need to do something with those numbers,
// Parse it.
Let me know if that works for you.
It seems like a reasonable approach, but I'd make a couple of changes from what you suggested:
If you need to result as a string then use a StringBuilder instead of an array.
Use character literals like '0' and '9' instead of ASCII codes to make your code more readable.
Update
The specific problem with your code is this line:
temp = temp + (int)c;
This converts the character to its ASCII value and then converts that to a decimal string containing the ASCII value. That's not what you want. Use this instead:
temp += c;