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16 Cards in this Set
- Front
- Back
Identifiers MUST start with what characters?
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a letter
a currency character ($, euro, yen etc) a connecting character (e.g. _) |
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Can an identifier start with a number?
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No
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What characters are valid in an identifier after the first character
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no limitation
any combination of letters, numbers, currency characters or connecting characters |
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Is there a limit to the number of characters an identifier can contain?
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No
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what is the format of an octal literal?
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A string of digits between 0 and 7, beginning with the digit 0
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How many access modifiers are there, and what are their names?
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public
protected default (package) private |
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What is the difference between protected access and default/package access?
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Protected access allows (inheritence) access for member or methods to subclasses in ANY package
Default/Package access ONLY allows access (reference or inheritence) to classes or subclasses in the same package |
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Which of the following declarations are legal?
a) void doStuff(int x...){} b) void doStuff(char...y, int x){} c) void doStuff(int x, char... c){} d) void doStuff(int x, float ...f){} e) void doStuff(int...i, String...s){} |
c) void doStuff(int x, char...c){}
The rules for var-arg declarations are: 1. The syntax for a var-arg declaration is type... varName (i.e. a valid type followed immediately by an ellipsis [...] followed by a variable name) 2. Only 1 var-arg parameter is permitted in a method signature 3. If a signature includes a var-arg it MUST be the last parameter in the signature |
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Which of the following modifiers are permitted on a constructor declaration?
public protected private static abstract strictfp synchronized native final |
access modifiers (public, protected ..)
strictfp synchronized native |
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Is it legal to declare a constructor in an abstract class?
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yes (check), but it isn't legal to call a constructor in an abstract class (an abstract class cannot be instantiated)
The constructor could only be called for a concrete class which extended the abstract class and provided implementations for any abstract methods |
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Is it possible to call a concrete method in an abstract class?
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yes (as long as the method is static and called as a class method)
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Where can an enum be defined?
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1) Outside of all classes (in a class file with other classes)
2) As a class member (within a class, but outside of all methods) Note: An enum cannot be defined within a method |
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What access modifiers are permitted with an enum definition?
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public or default/package
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What implicit modifiers are associated with ALL Interface constants?
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public static final
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Is it legal to define a class as abstract if it contains no abstract methods?
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Yes
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What modifiers are associated with all interface methods regardless of their signature?
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public abstract
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