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Primitive Types 2 questions
Types
- For each Java primitive type explain its purpose, its default value, its value range
Literals
- For the char literals, explain the meaning of \u, \n, \t, \', \" literals
- For the integral literals, only the decimal notation is covered (neither octal nor hexadecimal)
- For the floating point literals
- explain the meaning of the e, f, d suffixes
- use the Float/Double.NaN, .NEGATIVE_INFINITY, .POSITIVE_INFINITY constants
- Use the L(l) suffix to get a long literal instead of an int
Conversion
- Explain the widening conversion chain byte -> short -> int -> long -> float -> double
- Given code, spot valid and invalid primitive types casting operations
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6 |
30 |
5 |
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Flow Control 2 questions
Create Loops
- Write code using all kind of Java loops : for, while, do-while and for each (introduced in Java 5)
- Predict behavior of nested loops
- Use break and continue in nested loops, both unlabeled and labeled syntaxes.
Define Branching
- Write syntactically correct tests using if, switch structures
- Define correct types of arguments for both keywords
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5 |
40 |
5 |
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Ternary Operator 2 questions
- Use correct syntax and explain the ternary x ? y : z operator
- Identify correct operands and return type compatibility
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6 |
12 |
2 |
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static 3 questions
- Write code that defines class attributes using the static keyword and manipulate them
- Define class method, explain how to call them
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6 |
9 |
10 |
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final 2 questions
- Explain how to define constant attributes using final
- Identify places where blank final can be initialized
- Describe the meaning of final applied to methods
- Prevent classes from being subclassed by declaring them final
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6 |
19 |
0 |
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Class Loading 2 questions
- Explain the Java SE classpath mechanism
- Understand the ClassLoader hierarchy and implications on the static scope.
- Given an object instance get its ClassLoader from its Class
- Get the system classloader using ClassLoader.getSystemClassLoader()
- Write code that uses ClassLoader to load external resources on the file system.
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4 |
0 |
3 |
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Lifecycle 3 questions
- Understand the new operator to create an object.
- Determine the initialization sequence of fields, static fields, static block, constructor, ancestor constructors
- Explain the use of this() and super() in constructors and identify where you can call them
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8 |
6 |
2 |
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Overloading 3 questions
- Explain the overloading mechanism
- Identify the method name, arguments types and order differentiates 2 method signatures
- Explain why the return type does not differentiate 2 methods
- Given code, determine method resolution behavior when using polymorphism in parameters including Java 5 Autoboxing and varargs
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5 |
4 |
4 |
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Inner Classes 3 questions
- Write code that define basic inner classes (anonymous or not)
- Explain the usage of the outer class "this", in the inner class
- Use final modifier for local variables in enclosing classes to get access to it
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5 |
20 |
5 |
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Annotations 3 questions
An introduction from IBM to Annotations is here .
The definition of Annotations can be found in chapter 9.6 & 9.7 of the Java Language Specification and in the description of the java.lang.annotation package.
- Identify code that use Annotations.
- Create code that use standard Annotations.
- Develop custom Annotations.
- Explain the advantages of Annotations.
- Describe what marker annotations and meta-annotations are and how to use them.
Not covered: EJB 3 specific things!
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6 |
19 |
3 |
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Generics 3 questions
The Generics Tutorial from Sun covers the basic knowledge that is necessary for this category.
- Create code that uses Generics.
- Describe the benefits of Generics.
- Develop code which deals with legacy code that is not generified.
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7 |
31 |
7 |
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Enums 3 questions
- Identify the goals of Typesafe Enums.
- Create enum constructors and explain how to create Enums.
- Write code that shows the correct and incorrect usage of Typesafe Enums.
- Use the methods in enums.
- Work with EnumSet and EnumMap.
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6 |
14 |
3 |
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Exceptions 3 questions
- Create and throw a custom exception class.
- Use the throws keyword.
- Know the java standard exception hierarchy for: Throwable, Error, OutOfMemoryError, Exception, RuntimeException, NullPointerException, IOException...
- Understand execution flow for nested try/catch/finally clauses.
- Understand and use nested exceptions.
- Differentiate checked and unchecked exceptions.
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7 |
19 |
5 |
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