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Start your free trialDaniel Schwemmlein
4,960 PointsHow do i check if a letter starts with m and that the second letter is uppercased?
Hey guys! So in this challenge I'm supposed to check if the fieldname starts with an m and then goes on with camelcased letters, so the m lowercased and everything else uppercased. If not I should throw an illegalargumentexception. I kind of know how to do the latter. but the first part I have no idea. Its probably something with char. Please help me. Thanks!
public class TeacherAssistant {
public static String validatedFieldName(String fieldName) {
// These things should be verified:
// 1. Member fields must start with an 'm'
// 2. The second letter in the field name must be uppercased to ensure camel-casing
// NOTE: To check if something is not equal use the != symbol. eg: 3 != 4
if (! isvalidatedFieldName) {
throw (illegalArgumentException iae) {
console.printf("Please try again");
}
}
return fieldName;
}
}
3 Answers
Ken Alger
Treehouse TeacherDaniel;
You can check the status of characters in fieldName
with the zero-based index method of charAt()
. For example we want to make sure that "fieldName.charAt(0) == 'm'
", or more specifically "fieldName.charAt(0) != 'm'
".
A couple of things with this challenge to consider with your code, when checking the second character you also need to check that it is a letter.
Hopefully that gets you pointed in the right direction.
Happy coding,
Ken
Daniel Schwemmlein
4,960 Pointsshould it look like this then?
Sorry, this one is really difficult for me
if (! isvalidatedFieldName) { fieldName.charAt(0) != 'm'; throw (illegalArgumentException iae) { console.printf("Please try again");
Ken Alger
Treehouse TeacherDaniel;
Inside the validatedFieldName
function, you can do something like:
if(fieldName.charAt(0) != 'm' ){
throw new IllegalArgumentException("Error, needs to start with letter 'm'.");
}
Then you will need to check the requirements for charAt(1)
to make sure that character passes as well.
Ken