Just some quick questions on using string - java

We have to make a program on printing initials, which seems pretty easy ok, but I don't know how to cut the string when the input is all on one line using the scanner class in.nextline();. I cant seem to find a way to cut the string using only string methods. Also, another problem arose when I have to also be able to adjust if there isn't a middle name either. if anyone can help me or lead me in the right direction that would be nice.

If you can use split function as you can see below:
String inputString=s.nextLine();
String [] str = inputString.split(" ");

If you want to have extract only first letter then -
import java.util.Scanner;
public class TestStringInput {
public static void main(String[] args) {
Scanner scan = new Scanner(System.in);
System.out.println("Please Enter the Name");
String input = scan.nextLine();
int value = input.indexOf(" ",input.indexOf(" "));
String result = input.substring(0,value);
System.out.println(result);
}
}
But if you want to Extract Starting 2 Initials then change this line-
int value = input.indexOf(" ",input.indexOf(" ")+1);

As Stephen mentioned, your question is about Java, consider re-tagging.
You can use a for loop to iterate through the string. Remember a string is an object. It would help a lot if you posted your code.

import java.util.Scanner;
public class HW03 {
public static void main (String args[])
{
Scanner in = new Scanner(System.in);
String str = "";
System.out.println("What are your first, middle and last names?");
str = in.nextLine();
}
}

Related

Java if (Yes or No Statement)

Hey there I got into some trouble with my java Code.
I try to code a bit around with java for a few hours and I dont know much thats why im asking. I learn best by trying but I get into so many problems.
So: I want the scanner to scan the next Statement and if its "ja" it should do the if thing etc.
The problem is, when i try to compile it it has an error with the = s.nextInt thing. In the console it says: "cannot find symbole". I tried so many things I dont know what to do. Allready tried so much.
import java.util.Scanner;
public class Brotcrunsher {
public static void main(String args[]) {
Scanner scan = new Scanner(System.in);
System.out.println ("Hallo");
System.out.println ("A flag has more then 1 color right?");
String a = s.NextInt();
if (a.equals("ja")) {
System.out.println ("You arent dumb, nice.");
} // end of if
else {
System.out.println ("You arentn a genie");
} // end of if-else
}
}
thanks in advance.
EDIT: Problem solved. Thank you for every awnser. I try my best to Tag my posts better and to format my code better
Here:
String a = s.NextInt();
You want a to be String (which makes sense, as you want to compare it against other Strings later on); so you better use:
String a = s.nextLine();
instead!
The other method a) does not exist and b) nextInt() ... returns a number, not a string
I can see two errors, firstly you are taking a string input from the command line user so your scanner must be "scanner.nextLine()" which takes a string, as it stands you are expecting an integer value.
Second your "s.scanner" is not calling anything, you have declared your scanner with the name "scan", so you need to change that to "scan".
import java.util.Scanner;
public static void main(String[] args) {
Scanner scan = new Scanner(System.in);
System.out.println("A flag has more than one colour?");
String input = scan.nextLine();
if (input.equals("yes")) {
System.out.println("well done");
} else {
System.out.println("wrong answer");
}
}
Try:
import java.util.Scanner;
public class Brotcrunsher {
public static void main(String args[]){
Scanner scan = new Scanner(System.in);
System.out.println ("Hallo");
System.out.println ("A flag has more then 1 color right?");
String a = scan.nextLine();
if (a.equals("ja")) {
System.out.println ("You arent dumb, nice.");
} // end of if
else {
System.out.println ("You arentn a genie");
} // end of if-else
}
}
You have got a compilation error that should be
String a = scan.next();
Since scan is your scanner object where you are using String a = s.NextInt(); which is not at all an object of scanner.
Two issues, one is a is a String not an int and the second is Scanner.nextLine() (or nextInt() or next()). And, the local reference is scan (not s). Like,
String a = scan.nextLine();
You can use like this.
import java.util.Scanner;
class ScannerTest{
public static void main(String args[]){
Scanner sc=new Scanner(System.in);
System.out.println("Enter your rollno");
int rollno=sc.nextInt();
System.out.println("Enter your name");
String name=sc.next();
System.out.println("Enter your fee");
double fee=sc.nextDouble();
System.out.println("Rollno:"+rollno+" name:"+name+" fee:"+fee);
sc.close();
}
}
refrence: http://www.javatpoint.com/Scanner-class

Java User input related

I want to take input form user, i am sure my code is right but it don't work at all. Please help is there any thing that i am doing wrong?
`public void edit() throws IOException {
sll.insertAfter();
System.out.println("Enter text: ");
String sen;
sen = keyboard.next();
Object obj = sen;
sll.put(obj);
}
when i execute this an error appears at this line
sen = keyboard.next();
import java.util.*;
public class Example
{
public static void main(String[] args)
{
Edit();
}
public static void Edit()
{
Scanner scan = new Scanner(System.in);
String random;
System.out.print("Please input some text: ");
random = scan.nextLine();
System.out.println("You entered: " + random);
}
}
I don't know what your main method looks like so I can only assume it's empty That being said I can tell you why your current code doesn't work based off of the information you've given us.
Your edit method is not static, and in this situation assuming you've laid out your program simillar to this it must be static as it is in my example.
You've not setup a scanner, or maybe you did outside of your edit method but failed to make it static?
Scanner scan = new Scanner(System.in);
Why are you using Object, if you want to edit the string just use a for loop and substring.
Object
If you provide us with more information, your full code and the error you're getting we can better help you!

Removing a word in Java Program

I am having trouble getting my program to produce the exact output I would like it to. My program currently will remove any one instance of a string in a sentence the user inputs (Ex: Sentence- Hello there– String to be removed Hello and Output there).
What I would like to do is add something else so that the program will remove any and all instances of the string the user would like omitted (Ex: Hello there there in my current program, it would output Hello there. What I would like is it to simply print Hello). Can someone give me any idea on how to implement this. Thanks!
(Im also rather new to coding, so if you have an input on my code as is, please feel free to correct it)
Here is my current code:
import java.util.Scanner;
public class RemoveWord
{
Scanner scan = new Scanner(System.in);
String sentence;
String word;
public void removing()
{
System.out.println("Please enter a sentence");
sentence = scan.nextLine();
System.out.println("Please enter a word you would like removed from the sentence");
word = scan.nextLine();
int start = sentence.indexOf(word), end=0;
while(start!=-1)
{
sentence = sentence.substring(0, start) + sentence.substring(start+word.length());
end = start+word.length();
if(end>=sentence.length())
break;
start = sentence.indexOf(word, end);
}
System.out.println(sentence);
}
}
public class RemoveWordR
{
public static void main(String[]args)
{
RemoveWord r1 = new RemoveWord();
r1.removing();
}//main
}//class
Your problem is with end, because indexOf(x,y) check for occurrence of x after index y. It is int indexOf(String str, int fromIndex)
while(start!=-1)
{
sentence = sentence.substring(0, start) + sentence.substring(start+word.length());
end = start+word.length();
if(end>=sentence.length())
break;
start = sentence.indexOf(word, 0); //this line must be 0 or nothing
}
replaceAll() method provided by a string should replace all occurrences of a given word in the string
Example:
sentence.replaceAll("there","")
or
sentence.removeAll("there")

String.replace() method not printing full string in java

I'm trying to do some homework for my computer science class and I can't seem to figure this one out. The question is:
Write a program that reads a line of text and then displays the line, but with the first occurrence of hate changed to love.
This sounded like a basic problem, so I went ahead and wrote this up:
import java.util.Scanner;
public class question {
public static void main(String[] args)
{
Scanner keyboard = new Scanner(System.in);
System.out.println("Enter a line of text:");
String text = keyboard.next();
System.out.println("I have rephrased that line to read:");
System.out.println(text.replaceFirst("hate", "love"));
}
}
I expect a string input of "I hate you" to read "I love you", but all it outputs is "I". When it detects the first occurrence of the word I'm trying to replace, it removes the rest of the string, unless it's the first word of the string. For instance, if I just input "hate", it will change it to "love". I've looked at many sites and documentations, and I believe I'm following the correct steps. If anyone could explain what I'm doing wrong here so that it does display the full string with the replaced word, that would be fantastic.
Thank you!
Your mistake was on the keyboard.next() call. This reads the first (space-separated) word. You want to use keyboard.nextLine() instead, as that reads a whole line (which is what your input is in this case).
Revised, your code looks like this:
import java.util.Scanner;
public class question {
public static void main(String[] args)
{
Scanner keyboard = new Scanner(System.in);
System.out.println("Enter a line of text:");
String text = keyboard.nextLine();
System.out.println("I have rephrased that line to read:");
System.out.println(text.replaceFirst("hate", "love"));
}
}
Try getting the whole line like this, instead of just the first token:
String text = keyboard.nextLine();
keyboard.next() only reads the next token.
Use keyboard.nextLine() to read the entire line.
In your current code, if you print the contents of text before the replace you will see that only I has been taken as input.
As an alternate answer, build a while loop and look for the word in question:
import java.util.Scanner;
public class question {
public static void main(String[] args)
{
// Start with the word we want to replace
String findStr = "hate";
// and the word we will replace it with
String replaceStr = "love";
// Need a place to put the response
StringBuilder response = new StringBuilder();
Scanner keyboard = new Scanner(System.in);
System.out.println("Enter a line of text:");
System.out.println("<Remember to end the stream with Ctrl-Z>");
String text = null;
while(keyboard.hasNext())
{
// Make sure we have a space between characters
if(text != null)
{
response.append(' ');
}
text = keyboard.next();
if(findStr.compareToIgnoreCase(text)==0)
{
// Found the word so replace it
response.append(replaceStr);
}
else
{
// Otherwise just return what was entered.
response.append(text);
}
}
System.out.println("I have rephrased that line to read:");
System.out.println(response.toString());
}
}
Takes advantage of the Scanner returning one word at a time. The matching will fail if the word is followed by a punctuation mark though. Anyway, this is the answer that popped into my head when I read the question.

What did I do wrong in my program?

I am writing a program where if someone types in the following two lines:
HELLO, I’D LIKE TO ORDER A FZGH
KID’S MEAL
The program will output it like this:
HELLO, I’D LIKE TO ORDER A KID’S MEAL
In other words, the "FZGH" the user inputs into the sentence will be replaced with the second line's words, as you can see: the "FZGH" is replaced by "KID'S MEAL." Kinda get what I mean? If not, I can elaborate more but this is the best I can explain it as.
I'm really close to solving this! My current output is: HELLO, I’D LIKE TO ORDER A FZGH KID’S MEAL
My program didn't replace the "FZGH" with "KID'S MEAL," and I don't know why that is. I thought that by using the .replaceAll() thingy, it would replace "FZGH" with the "KID'S MEAL," but that didn't really happen. Here is my program so far:
public static void main(String[] args) {
sentences();
}
public static void sentences() {
Scanner console = new Scanner(System.in);
String sentence1 = console.nextLine();
String sentence2 = console.nextLine();
//System.out.println(sentence1 + "\n" + sentence2);
String word = sentence1.replaceAll("[FZGH]", "");
word = sentence2;
System.out.print(sentence1 + word);
}
Where did I mess up, resulting in the FZGH still appearing in output?
Use
sentence1 = sentence1.replaceAll("FZGH", "");
String word = sentence2;
Your first (and primary) problem is that you're creating a new String named word, that you're setting to the value of sentence1.replaceAll("[FZGH]", ""). You're then changing the value of word to be sentence2 immediately afterward, so the replacement is lost.
Instead, setting sentence1 to sentence1.replaceAll("FZGH", ""); will change sentence1 to no longer contain the string "FZGH", which is what you're going for. You don't actually need a word value at all, so if you'd like to remove it, it wouldn't hurt.
In addition, using [FZGH] will replace all F's, Z's, G's, and H's from the string- you should use FZGH instead, as this will only remove instances of all four letters in a row.
I think you have a couple of mistakes. Maybe the following is close...
public static void main(String[] args) {
sentences();
}
public static void sentences() {
Scanner console = new Scanner(System.in);
String sentence1 = console.nextLine();
String sentence2 = console.nextLine();
String sentence3 = sentence1+sentence2;
String final = sentence3.replaceAll("FZGH", "");
System.out.print(final);
}
You are reassigning the string "word"
in place of lines :
String word = sentence1.replaceAll("[FZGH]", "");
word = sentence2;
System.out.print(sentence1 + word);
use the following lines
sentence1 = sentence1.replaceAll("[FZGH]", "");
System.out.print(sentence1 + sentence2);
Actually replace method return a string that should be assign again to sentence1. you can run this code its works fine.
public static void main(String[] args) {
sentences();
}
public static void sentences() {
Scanner console = new Scanner(System.in);
String sentence1 = "HELLO, I’D LIKE TO ORDER A FZGH";
String sentence2 = "KID’S MEAL";
//System.out.println(sentence1 + "\n" + sentence2);
sentence1 = sentence1.replace("FZGH", "");
String word = sentence2;
System.out.print(sentence1 + word);
}

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