Java Homework Assignment — java.util.NoSuchElementException: No line found - java

I get an error from automated JUnit 4 unit testing software that my course instructor uses to automatically check assignments.
We upload our draft code to a cloud program tester which automatically checks and grades the assignments.
This is week 1 of first semester. I've never coded in Java before. And the lessons haven't taught if/else, while, loops, switch etc. so I don't think it's okay to use those (they appear next module.)
I followed a class video tutorial, which doesn't throw any exceptions in the tutorial — so I don't know what's going on.
The unit was on variables, input, printing out, Booleans, operators, and a few things like contains, replace, equals etc.
Note: I am allowed to ask questions on StackOverflow per instructor.
The error is: java.util.NoSuchElementException: No line found
No line number is specified in the testing software where the exception occurs. And since it's not happening in my IDE, I don't know where it is.
Other solutions I've found require while and other methods I'm not supposed to use.
My code (below) runs okay in the VSCODE IDE cloud the school provided.
import java.util.Scanner;
public class ContainsAnyCase {
public static void main(String[] args) {
System.out.println("Type a word:\n");
Scanner userInputWord = new Scanner(System.in);
String word = userInputWord.nextLine();
String wordlc = word.toLowerCase();
System.out.println("Type a sentence:\n");
Scanner userInputSentence = new Scanner(System.in);
String sentence = userInputSentence.nextLine();
String sentencelc = sentence.toLowerCase();
boolean isContains = sentencelc.contains(wordlc);
System.out.println(isContains);
}
}
I'm wondering if anyone can explain why there is an error and if there are ways to fix it or avoid the error without going into the territory of future modules? Also, I'm still learning how to use Stack Overflow appropriately. If I asked my question wrong, please advise how I can improve my question or post. Thank you.
I expected for the program to tell me true/false if the word was in the sentence. In my IDE, it worked. When I uploaded it to the JUnit4, it said java.util.NoSuchElementException: No line found

Here's an example of using just ONE SCANNER as suggested in the comments.
I've also eliminated the second set of variables for lower case; just convert the input directly to lower case and store it in the original variable:
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
System.out.println("Type a word:\n");
String word = sc.nextLine().toLowerCase();
System.out.println("Type a sentence:\n");
String sentence = sc.nextLine().toLowerCase();
boolean isContains = sentence.contains(word);
System.out.println(isContains);
}
If you need to preserve the exact user input for later, then you can convert to lower case only when you call contains() like this:
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
System.out.println("Type a word:\n");
String word = sc.nextLine();
System.out.println("Type a sentence:\n");
String sentence = sc.nextLine();
boolean isContains = sentence.toLowerCase().contains(word.toLowerCase());
System.out.println(isContains);
}

Related

Display elements of a String which are not found on the other

We were told to do a program on stings and I wasn't able to attend class because I was sick. I am asking for your help on this task that was given to us.
Create a java program that will ask the user to input two Strings. Compare the two strings and display the letters that are found on the first string but are not found on the second string.
Here is what I have at the moment https://pastebin.com/7a4dHecR
I really have no Idea what to do so any help would be appreciated!
https://pastebin.com/7a4dHecR
import java.util.*;
public class filename{
public static void main(String[] args){
Scanner sc =new Scanner(System.in);
System.out.print("Input first string: ");
String one=sc.next();
System.out.println();
System.out.print("Input second string: ");
String two=sc.next();
}
}
There are many ways to do this. I'm going to give you some parts you can put together. They are not the shortest or simplest way to solve this particular problem, but they will be useful for other small programs you write.
Here are some hints:
First, figure out how to step through your code with a debugger.
Second, figure out how to find the Javadoc for Java library classes and their methods.
You need to do something for each character in a string. Use a for loop for that:
for (int i = 0; i < one.length(); i++) {
// your code here
}
You need to get a particular character of a String.
String c = one.substring(i, i+1);
Read the Javadoc for String.substring to understand what the i and i+1 parameters do.
Now you need to find a way to check whether a String contains another String. Look at the Javadoc for the String class.
Then you can put all this together.
You could try the following:
String diff: StringUtils.difference(one, two);
System.out.println(diff);

Finding hashtags in a input string from a user [duplicate]

I am very new to Java but am working through the book Java: How to program (9th ed.) and have reached an example where for the life of me I cannot figure out what the problem is.
Here is a (slightly) augmented version of the source code example in the textbook:
import java.util.Scanner;
public class Addition {
public static void main(String[] args) {
// creates a scanner to obtain input from a command window
Scanner input = new Scanner(System.in);
int number1; // first number to add
int number2; // second number to add
int sum; // sum of 1 & 2
System.out.print("Enter First Integer: "); // prompt
number1 = input.nextInt(); // reads first number inputted by user
System.out.print("Enter Second Integer: "); // prompt 2
number2 = input.nextInt(); // reads second number from user
sum = number1 + number2; // addition takes place, then stores the total of the two numbers in sum
System.out.printf( "Sum is %d\n", sum ); // displays the sum on screen
} // end method main
} // end class Addition
I am getting the 'NoSuchElementException' error:
Exception in thread "main" java.util.NoSuchElementException
at java.util.Scanner.throwFor(Scanner.java:838)
at java.util.Scanner.next(Scanner.java:1461)
at java.util.Scanner.nextInt(Scanner.java:2091)
at java.util.Scanner.nextInt(Scanner.java:2050)
at Addition.main(Addition.java:16)
Enter First Integer:
I understand that this is probably due to something in the source code that is incompatible with the Scanner class from java.util, but I really can't get any further than this in terms of deducing what the problem is.
NoSuchElementException Thrown by the nextElement method of an Enumeration to indicate that there are no more elements in the enumeration.
http://docs.oracle.com/javase/7/docs/api/java/util/NoSuchElementException.html
How about this :
if(input.hasNextInt() )
number1 = input.nextInt(); // if there is another number
else
number1 = 0; // nothing added in the input
You should use hasNextInt() before assigning value to variable.
NoSuchElementException will be thrown if no more tokens are available. This is caused by invoking nextInt() without checking if there's any integer available. To prevent it from happening, you may consider using hasNextInt() to check if any more tokens are available.
I faced this Error with nextDouble(), when I input numbers such as 5.3, 23.8 ... I think that was from my PC depending on computer settings that use Arabic (23,33 instead 23.33), I fixed it with add:
Scanner scanner = new Scanner(System.in).useLocale(Locale.US);
You must add input.close() at the end...
This error is mostly occur in case of 0nline IDE's on which you are testing your code. It is not configured properly, as if you run the same code on any other IDE/Notepad it works properly because the online IDE is not designed such a way that it will adjust the input code of your format, So you have to take input as the Online IDE supports.
If I may, I solved this issue today by realizing that I had multiple functions that used an instance of a Scanner, each. So basically, try refactoring so that you have only one instance opened and then closed in the end - this should work.
For anyone using gradle's application plugin, you must wire it to the standard console in build.gradle(.kts) otherwise it will keep throwing the NoSuchElementException error if you try to use scanner.
For groovy:
run {
standardInput = System.in}
For gradle kotlin dsl:
tasks.withType<JavaExec>() {
standardInput = System.`in`}
Integer#nextInt throws NoSuchElementException - if input is exhausted
You should check if there is a next line with Integer#hasNextLine
if(sc.hasNextLine()){
number1=sc.nextInt();
}
I added a single static scanner (sc) at the top of my class and closed it (sc.close()) when coming out of the whole class wherever I used return statements. Again that's one instance of scanner as suggested by another answer, which should be static.
package com.example.com;
import java.util.Scanner;
public class someClass {
static Scanner sc = new Scanner(System.in);
//Whole world of methods using same sc.
//sc.close()); return;
}
Other than that you can add #SuppressWarnings("resource") on the top of the troubling method to make the warning go away. But be careful about resource leaks.

Can't get program to break on specific string [duplicate]

This question already has answers here:
Scanner only reads first word instead of line
(5 answers)
Closed 2 years ago.
The code works for the most part, but if I type "No way" it still stops the loop. Should I set it up a different way or use a length function ? Everything I've searched on breaking a loop used integers.
See the code below:
import java.util.Scanner;
public class CarryOn {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
while (true) {
System.out.println("Shall we carry on?");
String answer = String.valueOf(scanner.next());
if (answer.equalsIgnoreCase("no")){
break;
}
}
}
}
Using .next in this case only stores "no" in "no way". Use .nextLine instead:
Scanner scanner = new Scanner(System.in);
while (true) {
System.out.println("Shall we carry on?");
String answer = String.valueOf(scanner.nextLine());
if (answer.equalsIgnoreCase("no")){
break;
}
}
Output:
Shall we carry on?
no way
Shall we carry on?
no
Check this post for more information.
scanner.next()
only reads a single token. No way is two tokens: No and way.
Use scanner.nextLine() instead, if you want to read the whole line.

Is it possible to add an or condition to an if statement in java?

So recently I've switched over from python to java and was trying to recreate some of the projects that I made on python in java. The first thing that came to mind was a quiz.
Basically, to create a quiz, I define an answer variable to the answer then use the scanner method in java to detect the user's input. After that, I use an if statement to see if the input equals the answer.
ex.
class Main {
public static void main(String[] args) {
Scanner scan = new Scanner(System.in);
String answer = "dog";
System.out.println("What is a common furry animal");
String input = scan.nextLine( );
if (input.equals(answer))
{
System.out.println("Correct");
}
else
{
System.out.println("Inncorect");
}
}
}
Now that all works but the user doesn't know the exact casing of the answer variable which means if the variable was "dog" and he input "Dog" it would be incorrect. So if it was possible to create an "or" condition to an if statement it would be awesome if someone let me know.
-Thanks
To or any condition in Java, use the conventional || to separate conditions. In your case it would be something like:
if (input.equals(answer) || input.equalsIgnoreCase(answer))
Although you probably just need the Java method equalsIgnoreCase as the lone condition in the first place.

else is not working when called by function

public static void main(String[] args) {
//For String
Scanner input = new Scanner(System.in);
//For Letter
Scanner word = new Scanner(System.in);
String name;
//Input For a String
System.out.println("Enter A String");
name = input.nextLine();
//Input For a Char
char letter[] = new char[3];
System.out.println("Enter a Letter You Want to Search ");
for(char c : letter)
letter = word.nextLine().toCharArray();
elfish(letter, name);
}
public static void elfish(char letter[], String name) {
if(name.toLowerCase().contains(name.valueOf(letter).toLowerCase())) {
System.out.println("Yes The Letter Contains Elfish");
} else {
System.out.println("You're Word is not in this String");
}
}
i m making the program which is near to completion. It actually searches the desired letter in the string and if condition is true is prints the "if block" and if condition is false "else block" should run but actually its not working now. only "if block" is working. "else block" was also working fine until it was directly placed in main function. please tell me where what is wrong.
You're trying to iterate through letter before putting anything in the array. If you take out the for loop, (leaving the assignment of letter) the code should run properly in many cases. I do not know how you want to validate input.
I'm guessing you are new. Learning to use a debugger can be overwhelming, but it is a powerful tool. It'll be slightly different for every debugger and IDE but the process is the same.
A little more info here: Breakpoints and step by step debug in Java?
However, in this instance finding a guide for your IDE on Google might be the best option.

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