Methods: How to Write Them - AP Computer Science A
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Identify the error in this method: 'public static void main()'
Identify the error in this method: 'public static void main()'
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Add parameter: '(String[] args)'. Main method requires String array parameter for command-line arguments.
Add parameter: '(String[] args)'. Main method requires String array parameter for command-line arguments.
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Identify the error: 'void calculate() { return 5; }'
Identify the error: 'void calculate() { return 5; }'
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Remove 'return 5;' since return type is void. Void methods cannot return values, only perform actions.
Remove 'return 5;' since return type is void. Void methods cannot return values, only perform actions.
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How can a method in Java be overloaded?
How can a method in Java be overloaded?
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By changing the number or type of parameters. Different parameter signatures enable method overloading.
By changing the number or type of parameters. Different parameter signatures enable method overloading.
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What is the syntax for defining a method in Java?
What is the syntax for defining a method in Java?
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accessModifier returnType methodName(parameters) { body }. Standard Java method structure with access modifier, return type, name, and parameters.
accessModifier returnType methodName(parameters) { body }. Standard Java method structure with access modifier, return type, name, and parameters.
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What keyword is used to return a value from a method?
What keyword is used to return a value from a method?
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return. Exits the method and sends a value back to the caller.
return. Exits the method and sends a value back to the caller.
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What is the purpose of the 'return' statement?
What is the purpose of the 'return' statement?
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To exit a method and optionally return a value. Controls method flow and passes data back to caller.
To exit a method and optionally return a value. Controls method flow and passes data back to caller.
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What is the purpose of a method signature?
What is the purpose of a method signature?
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To uniquely identify a method with its name and parameters. Distinguishes methods by combining name with parameter types.
To uniquely identify a method with its name and parameters. Distinguishes methods by combining name with parameter types.
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Which keyword is used to define a method that cannot be overridden?
Which keyword is used to define a method that cannot be overridden?
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final. Prevents subclasses from overriding the method implementation.
final. Prevents subclasses from overriding the method implementation.
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Find and correct the error: 'public int add(a, b) { return a + b; }'
Find and correct the error: 'public int add(a, b) { return a + b; }'
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Specify parameter types: 'int a, int b'. Parameters must include data types for compilation.
Specify parameter types: 'int a, int b'. Parameters must include data types for compilation.
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What does 'static' mean when used in a method declaration?
What does 'static' mean when used in a method declaration?
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The method belongs to the class, not instances of the class. Can be called using the class name without creating objects.
The method belongs to the class, not instances of the class. Can be called using the class name without creating objects.
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Which keyword allows a method to be used without a class instance?
Which keyword allows a method to be used without a class instance?
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static. Enables calling methods without instantiating the class.
static. Enables calling methods without instantiating the class.
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What is a parameter in the context of a method?
What is a parameter in the context of a method?
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A variable listed in the method's declaration. Receives values when the method is called.
A variable listed in the method's declaration. Receives values when the method is called.
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Identify the error: 'public void print() { System.out.println('Hello'); }'
Identify the error: 'public void print() { System.out.println('Hello'); }'
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Use double quotes: "Hello". String literals require double quotes, not single quotes.
Use double quotes: "Hello". String literals require double quotes, not single quotes.
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What is the return type of a constructor?
What is the return type of a constructor?
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Constructors do not have a return type. Constructors initialize objects and don't return values explicitly.
Constructors do not have a return type. Constructors initialize objects and don't return values explicitly.
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What must match between a method call and its definition?
What must match between a method call and its definition?
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The number and types of parameters. Ensures proper method invocation with correct argument types.
The number and types of parameters. Ensures proper method invocation with correct argument types.
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What is the purpose of the 'this' keyword in a method?
What is the purpose of the 'this' keyword in a method?
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To refer to the current object instance. Distinguishes instance variables from parameters or local variables.
To refer to the current object instance. Distinguishes instance variables from parameters or local variables.
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How do you indicate that a method can throw an exception?
How do you indicate that a method can throw an exception?
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Use the 'throws' keyword in the method declaration. Declares potential exceptions that may occur during execution.
Use the 'throws' keyword in the method declaration. Declares potential exceptions that may occur during execution.
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Why would you use a method with a void return type?
Why would you use a method with a void return type?
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For methods that perform actions but do not return values. Suitable for operations like printing or modifying object state.
For methods that perform actions but do not return values. Suitable for operations like printing or modifying object state.
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Identify the error: 'public static void main(String args[])'
Identify the error: 'public static void main(String args[])'
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Use 'String[] args' for the parameter. The main method requires proper array syntax for command-line arguments.
Use 'String[] args' for the parameter. The main method requires proper array syntax for command-line arguments.
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What is the effect of method overloading in Java?
What is the effect of method overloading in Java?
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Allows different implementations for different parameter lists. Provides flexibility by supporting various parameter combinations.
Allows different implementations for different parameter lists. Provides flexibility by supporting various parameter combinations.
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What is a method's access modifier?
What is a method's access modifier?
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Specifies the visibility of the method to other classes. Controls which classes can access and use the method.
Specifies the visibility of the method to other classes. Controls which classes can access and use the method.
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Identify the error: 'void calculate() { return 5; }'
Identify the error: 'void calculate() { return 5; }'
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Remove 'return 5;' since return type is void. Void methods cannot return values, only perform actions.
Remove 'return 5;' since return type is void. Void methods cannot return values, only perform actions.
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What is the difference between parameters and arguments?
What is the difference between parameters and arguments?
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Parameters are in the method declaration, arguments are in the call. Parameters define method interface; arguments are actual values passed.
Parameters are in the method declaration, arguments are in the call. Parameters define method interface; arguments are actual values passed.
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Which option correctly calls a method named 'display' with an int parameter?
Which option correctly calls a method named 'display' with an int parameter?
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display(5). Proper method call syntax with parentheses and argument.
display(5). Proper method call syntax with parentheses and argument.
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Identify the error: 'public int add(int a, int b) return a + b;'
Identify the error: 'public int add(int a, int b) return a + b;'
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Add curly braces: '{ return a + b; }'. Method body requires curly braces to contain executable code.
Add curly braces: '{ return a + b; }'. Method body requires curly braces to contain executable code.
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What is the 'main' method in Java?
What is the 'main' method in Java?
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The entry point of a Java application: 'public static void main(String[] args)'. Special method where program execution begins in Java applications.
The entry point of a Java application: 'public static void main(String[] args)'. Special method where program execution begins in Java applications.
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What is the purpose of an abstract method?
What is the purpose of an abstract method?
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To be implemented by subclasses in an abstract class. Forces subclasses to provide concrete implementation.
To be implemented by subclasses in an abstract class. Forces subclasses to provide concrete implementation.
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How do you document a method in Java?
How do you document a method in Java?
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Use Javadoc comments: '/** ... */'. Standard documentation format for generating API documentation.
Use Javadoc comments: '/** ... */'. Standard documentation format for generating API documentation.
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Which keyword allows a method to be used without a class instance?
Which keyword allows a method to be used without a class instance?
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static. Enables calling methods without instantiating the class.
static. Enables calling methods without instantiating the class.
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What is the purpose of a constructor?
What is the purpose of a constructor?
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To initialize a new object of a class. Special method called when creating new class instances.
To initialize a new object of a class. Special method called when creating new class instances.
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