Another question about string!

Question

Hi,
I want to return a function as true if all the characters in that string are hexDigit. false otherwise.
& also another class should return as true if all the charaters are Digit. false otherwise i was using
public boolean isDigit(String str)
for (int i=0; I<str.length(); i++)
if (str.charAt(i).isDigit)
return true
return false
what's wrong with this code? what shall I use instead of this? can anyone Help please?

Answer 1

The way you've written it, you'll be returning true as soon as the first digit in the string is found:
// on first loop will check first char in string.
if(str.charAt(i)isDigit)
// first char in string is a digit so method returns true
return true;
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You could change it so that you will return false when non-numerical character is found. If none is found you will fall out the loop and return true.if(!str.charAt(i).isDigit)
return false;
return true;
[\code]
Don't know if there's a method for checking hexDigit. If not use something like:
if (str.charAt(x).isDigit || str.charAt(x) >='A' && str.charAt(x) <='F');
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