Input Using Scanner Class

[Santosh Kumar Nayak]

Any way to make take run time input using Scanner Class ?

Scanner sc = new Scanner(System.in);
        System.out.println("Press X to stop Input ");    
        String str = ""; String s1 = "";     
        if(!(sc.next().equals("X"))){
        	 str = sc.next();
        	 s1 = s1.concat(str); 
        } 
        else { return ; } 
       System.out.println("Expression ="+ s1);   

Any Help on this would be appreciated !!!

[Campbell Ritchie]

That technique wll take input at runtime all right. Please count how often the if statement will run. Please also count how many inputs you need before the end of the if, which you do by counting the next() calls.

[Santosh Kumar Nayak]

import java.util.Scanner;

public class ScannerEx {

	public static void main(String[] args) {

       	  System.out.println("Enter of input elements opernads and operator count ");    
	        Scanner sc = new Scanner(System.in);
	        int count = sc.nextInt();
	        System.out.println("Provide your Input  string");
	        
	        String str = "";   
                String s1 = "";  
                int   noOfElements =0;
	        
while(noOfElements < count){
	        	Scanner scan  = new Scanner(System.in);
	        	str = scan.next();
	        	 s1 = s1.concat(str); 
	        } 
	       System.out.println("Expression ="+ s1);  
	   }
		
	}

Tried the above Code but does not work. It keeps taking Input from user

[Campbell Ritchie]

That is completely different code from what you had earlier, with different semantics. It looks as if you were guessing about different kinds of code, and guessing is always a bad idea. Don't create multiple Scanners reading System.in. Use one Scanner for System.in for the whole application and never close it.
Also, go through your loop and work out what happens to the loop variable (noOfElements) during the loop.

If you are trying to create an expression, why are you concatenating the whole thing into one String? Why don't you have classes for operators and operands and expressions? If you put the whole thing together into a String, you will have the same problem about breaking the String up later.

[Santosh Kumar Nayak]

public class ScannerEx {
	public static void main(String[] args) {
		System.out.println("Enter of input elements ");    
		Scanner sc = new Scanner(System.in);
		int count = sc.nextInt();
		System.out.println("Provide your Input Integers  ");
		int   noOfElements =0;
		while(noOfElements < count)
		{
			int i = sc.nextInt();   
			noOfElements++; 
			System.out.print ("noOfElements"+ noOfElements);  
		} 
		System.out.println(" Exiting while Loop ");
	}
}

THANKS This is what I was looking for ....