Thread: Why does my code always print out true.

Hello!

Consider this code

 
import java.util.Arrays;
public class test {
 
	static boolean isDigit(char ch) {
		if( '0' <= ch  && ch <='9') {
			Out.println("true");
			return true;
		} else {
			Out.println("false");
			return false;
		}
	}
 
 
 
	public static void main (String[] args) {
		Out.println("Put in a digit");
		char ch = In.readChar();
		isDigit(ch);
 
 
	}
 
 
}

Now the goal is to print out true whenever we input a number between 0 and 9,and for every other number we want to print out false.But for some reason it is always printing out true,no matter what number I put in.Worth mentioning is that the numbers are not int but char.Why does it print out true even for values of 120 ?

At what point in the code do I want to see the value of ch? When the user inputs the value?

Okay,very very interesting results;

for 12;

12
ch=49 1
true

for 8

8
ch=56 8
true

for 222

222
ch=50 2
true


The code

 
import java.util.Arrays;
public class test {
 
	static boolean isDigit(char ch) {
		if( '0' <= ch  && ch <='9') {
			Out.println("true");
			return true;
		} else {
			Out.println("false");
			return false;
		}
	}
 
 
 
	public static void main (String[] args) {
		Out.println("Put in a digit");
		char ch = In.readChar();
		System.out.println("ch=" + (int)ch + " " + ch);
		isDigit(ch);
 
 
	}
}

Yea I see it as well, the values of the char are single digit that is why its always printing true.Which means my logic wasnt at fault but the readChar() method.Thank you for your help,I'll adjust this with the method.