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Marcus Schumacher
16,616 PointsShouldn't this work?
Prompt:
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.
I don't understand why this isn't working.
public class TeacherAssistant {
public static String validatedFieldName(String fieldName) {
// These things should be verified:
// 1. Member fields must start with an 'm'
if(fieldName.indexOf(0) != "m") {
throw IllegalArgumentException("Field name does not start with an m");
}
// 2. The second letter in the field name must be uppercased to ensure camel-casing
if(fieldName.indexOf(0) != fieldName.indexOf(0).toUpperCase()) {
throw IllegalArgumentException("Your second letter must be an uppercase letter");
}
// NOTE: To check if something is not equal use the != symbol. eg: 3 != 4
return fieldName;
}
}
2 Answers
Ruud Claassen
9,359 PointsHi Markus, make sure you use the correct method to retrieve a character at a given position in a string.
.indexOf() returns the index number of a given character. In this case, using charAt() would be the way to go to retrieve a character at a given index number.
When throwing an exception, make sure to also include the 'new' keyword.
Java has some existing methods to check whether a character is uppercase or lowercase, for example with character 'c':
- Character.isUpperCase('c') (will return false)
- Character.isLowerCase('c') (will return true)
Perhaps you can now tweak your code so it works?
Ruud Claassen
9,359 Points- Make sure to use the .charAt() method
- Make sure to use the 'm' character instead of the "m" String
Your code for checking the uppercase should be fine.
public class TeacherAssistant {
public static String validatedFieldName(String fieldName) {
// These things should be verified:
// 1. Member fields must start with an 'm'
if( fieldName.charAt(0) != 'm' ){
throw new IllegalArgumentException("Field name does not start with an m");
}
// 2. The second letter in the field name must be uppercased to ensure camel-casing
boolean isUpperCase = Character.isUpperCase(fieldName.charAt(1));
if(!isUpperCase) {
throw new IllegalArgumentException("Your second letter must be an uppercase letter");
}
return fieldName;
}
}
Marcus Schumacher
16,616 PointsThanks that worked. I appreciate your help :)
Marcus Schumacher
16,616 PointsMarcus Schumacher
16,616 PointsI revised my code :( still doesn't work
public class TeacherAssistant {
public static String validatedFieldName(String fieldName) { public static String validatedFieldName(String fieldName) { // These things should be verified: // 1. Member fields must start with an 'm' if(fieldName.indexOf(0) != "m") { throw IllegalArgumentException("Field name does not start with an m"); } // 2. The second letter in the field name must be uppercased to ensure camel-casing
}
}