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João Albuquerque
1,642 PointsChallenge task 1
I got this error:
./TeacherAssistant.java:8: error: illegal start of expression if (fieldName.charAt(0) != 'm') && (Character.isUpperCase(fieldName.charAt(1)))) { ^ ./TeacherAssistant.java:8: error: ';' expected if (fieldName.charAt(0) != 'm') && (Character.isUpperCase(fieldName.charAt(1)))) { ^ 2 errors
what is wrong ?
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 (fieldName.charAt(0) != 'm') && (Character.isUpperCase(fieldName.charAt(1)))) {
throw new IllegalArgumentException("Error!");
}
return fieldName;
}
}
4 Answers
Jeremy Hill
29,567 PointsThis is what I did:
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 (fieldName.charAt(0) != 'm' || !Character.isUpperCase(fieldName.charAt(1))){
throw new IllegalArgumentException("Not a valid field name!");
}
return fieldName;
}
}
João Albuquerque
1,642 PointsAh yes , I thought I had to separate each expression with parentheses and I forgot that in the beginning. But one more question ... I should not use && as a member variable must start with 'm' AND the second letter must be uppercase.
I'm sorry for any grammar mistake, I 'm from Brazil :)
Jeremy Hill
29,567 PointsWhen you have an if statement with two conditions you will have either '&&' (and) or 'll' (or); when you use && this means that BOTH conditions HAVE to be met, and when you use 'll' only one of the two conditions need to be met, here is an example:
If(age <= 50 && wrinkles < 5) System.out.println("Not that old");
If(age > 50 ll wrinkles >=5) System.out.println("Kind of old")
I hope this helps.
Jeremy Hill
29,567 PointsAlso, the field name being referred to is a member variable, also known as a instance variable. The way treehouse teaches it is when you are declaring a member variable you use a lowercase 'm' followed by the name of your variable with the first letter of the name being capitalize; so if you were to declare a member variable for the word "size" it would look like this: mSize
The challenge wants you to make sure that whatever is passed in gets checked using the if statement to see if the first letter is a lowercase 'm' and the next letter is capitalized; if it isn't in that format an exception will be thrown.
João Albuquerque
1,642 PointsWow , now I understand it all . Thank you very much!
Jeremy Hill
29,567 PointsYou're welcome :)
Jeremy Hill
29,567 PointsJeremy Hill
29,567 PointsOne thing I noticed is your parenthesis- for your if statement you need an opening and a closing for everything inside; the closing one in your code was after the 'm' so everything after that was confusing the compiler.
Also I changed the '&&' to '||' that way either condition will throw the error instead of having to have a capital 'm' and an upper case letter next to it.
Also, I noticed that you didn't have a '!' in your second condition in your if statement so the program would have been looking to throw an exception had the second character been upper cased.