Sentinel-controlled loop

[hugo84]

Hi how can i use a sentinel controlled loop to keep prompting the user to enter the next character after it computes whether the char is a digit or a vowel till the user inputs a sentinel character '#' it will exit the program.

import java.util.Scanner;
class test1 {

public static void main(String[] args) {
Scanner zz= new Scanner(System.in);
System.out.println("Enter a character:");
String s = zz.next();
char input = s.charAt(0);


if (input=='a'||input=='e'||input=='i'||input=='o'||input=='u') {
System.out.println("Vowel");
}
else if(Character.isDigit(input))
{
System.out.println("Digit");
}

}
}

[holestary]

you asked this??

import java.util.Scanner;

class test1 {

public static void main(String[] args) {
Scanner zz= new Scanner(System.in);
System.out.println("Enter a STRING:");
String s = zz.next();
//char input = s.charAt(0);

for(int k=0;k<=s.length()-1;k++)
{
if (s.charAt(k)=='a'||s.charAt(k)=='e'||s.charAt(k)=='i'||s.charAt(k)=='o'||s.charAt(k)=='u') {
System.out.println("Vowel");
}
else if(Character.isDigit(s.charAt(k)))
{
System.out.println("Digit");
}
}
}
}


output:


Enter a STRING:
1necmi6
Digit
Vowel
Vowel
Digit

[hugo84]

Nope what i meant was to use a while loop then prompt for user to input character and compute whether the char is a digit or vowel. If user enter # then it will will break the loop.

So basically output will be:

Enter Character:
A
Vowel

Enter Character:
3
Digit

Enter Character:
E
Vowel

....
....
....
....
....
....

Enter Character:
#
// It will exit the program

[holestary]

according to me you can do this with do-while loop..

[hugo84]

im not sure i tried doing like this.. but it keeps looping forever.. please help

import java.util.Scanner;
class test1 {

public static void main(String[] args) {
Scanner zz= new Scanner(System.in);
System.out.println("Enter a character:");
String s = zz.next();
char input = s.charAt(0);

do{

if (input=='a'||input=='e'||input=='i'||input=='o'||input=='u') {
System.out.println("Vowel");
}
else if(Character.isDigit(input))
{
System.out.println("Digit");
}
}
System.out.println("Enter a Character again:");
while(input !='#');

}
}

[holestary]

import java.util.Scanner;
class test1 {

public static void main(String[] args) {
Scanner zz= new Scanner(System.in);
System.out.println("Enter a character:");
String s = zz.next();
char input = s.charAt(0);

do{
if (input=='a'||input=='e'||input=='i'||input=='o'||input=='u')
System.out.println("Vowel");

else if(Character.isDigit(input))
System.out.println("Digit");

else if(input=='#')
break;

System.out.println("\nEnter a character:");
s = zz.next();
input = s.charAt(0); //new value for input
}while(input !='#');

System.out.println("\n******");
}
}

[holestary]

while writing your codes use

[code][code] tags..

[holestary]

im not sure i tried doing like this.. but it keeps looping forever.. please help

import java.util.Scanner;
class test1 {

public static void main(String[] args) {
Scanner zz= new Scanner(System.in);
System.out.println("Enter a character:");
String s = zz.next();
char input = s.charAt(0);

do{

if (input=='a'||input=='e'||input=='i'||input=='o'||input=='u') {
System.out.println("Vowel");
}
else if(Character.isDigit(input))
{
System.out.println("Digit");
}
}
System.out.println("Enter a Character again:");
while(input !='#');

}
}

because you didn't give new value for "input"...always it controls input's first value and loops forever..

[hugo84]

Very much thanks to your help holstary. appreciate it dude. I will take note of the code posting tags very sorry about it.

[holestary]

u can write this instead of do-while..

while(input !='#')
{
if (input=='a'||input=='e'||input=='i'||input=='o'||input=='u')
System.out.println("Vowel");

else if(Character.isDigit(input))
System.out.println("Digit");

else if(input=='#')
break;

System.out.println("\nEnter a character:");
s = zz.next();
input = s.charAt(0); //new value for input
}

[dlorde]

u can write this instead of do-while..
... else if(input=='#')
break;

What is the point of that 'else if...' ?

Good teaching is more a giving of the right questions than a giving of the right answers...
J. Albers

[holestary]

What is the point of that 'else if...' ?

... else if(input=='#')
break;


Good teaching is more a giving of the right questions than a giving of the right answers...
J. Albers


i've missed out this code..it is unnecessary while using while loop in this prog..
i know u can do this program better than me, short, etc..:)
thanks..

[hugo84]

Thanks for the inputs.. Appreciate it