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Lucas Santos
19,315 PointsStuck on this challenge
So I was wondering if you could help me with some of these code challenges. As you might've seen when a member field name doesn't match the style we've talked about, I send an error about it. Let's write some code to validate the style of the field name.
I've added the method validatedFieldName it will return the validated field name. If the value passed in doesn't meet the requirements, throw an IllegalArgumentException. I'll keep you posted on the results every time you press check work.
WHAT I CAME UP WITH:
public class TeacherAssistant {
public static String validatedFieldName(String fieldName) {
// These things should be verified:
if(fieldName.charAt(0) != 'm' ){
throw new IllegalArgumentException("Letter must start with an M");
}
if( !Character.toUpperCase(fieldName.charAt(1))){
throw new IllegalArgumentException("Second letter must be capital");
}
// 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
return fieldName;
}
}
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
return fieldName;
}
}
2 Answers
Lucas Santos
19,315 PointsDid this challenge couple of times and actually found an better way to go about it.
Came up with this and passed:
public class TeacherAssistant {
public static String validatedFieldName(String fieldName) {
// These things should be verified:
char firstLetter = fieldName.charAt(0);
char secondLetter = fieldName.charAt(1);
// 1. Member fields must start with an 'm'
if(firstLetter != 'm'){
throw new IllegalArgumentException("first letter needs to start with m");
}
if( !Character.isLetter(secondLetter) || secondLetter != Character.toUpperCase(secondLetter)){
throw new IllegalArgumentException("second letter needs to be capital");
}
// 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
return fieldName;
}
}
Jess Sanders
12,086 Pointsprivate char validateGuess(char letter) {
if (!Character.isLetter(letter)) {
throw new IllegalArgumentException("A letter is required."
}
letter = Character.toLowerCase(letter);
if (mMisses.indexOf(letter) >= 0 || mHits.indexOf(letter) >= 0) {
throw new IllegalArgumentException(letter + " has already been guessed") }
return letter;
}
- The above code is the example to follow.
- We care about charAt for this challenge, rather than indexOf
- In pseudocode, we want to check for the following condition, and throw an error: " if the character at index 0 of fieldName does not equal 'm' OR the character at index 1 of fieldName is not upper case"