Java Fundamentals test 2

What are the different data types in Java?

• int, double, char, boolean, classes, interfaces, methods

• float, string, byte, long, void, objects

• int, double, char, boolean, classes, interfaces, arrays

• int, double, char, boolean, float, string, byte

Explain the difference between int and double data types in Java.

• The main difference between int and double data types in Java is that int stores whole numbers, while double stores floating-point numbers with decimal values.

• int and double are interchangeable and can be used interchangeably in Java

• int is used for text data, while double is used for numerical data

• int stores decimal numbers, while double stores whole numbers

What are the different types of operators in Java?

• Comparison

• Equality

• Shift

• Unary

• Arithmetic, Relational, Logical, Bitwise, Assignment, Conditional

What is the use of the 'if' statement in Java?

• The 'if' statement in Java is used to declare a new variable

• The 'if' statement in Java is used to make a decision based on a condition.

• The 'if' statement in Java is used to define a method

• The 'if' statement in Java is used for looping through a set of code multiple times

How are arrays declared and initialized in Java?

• dataType arrayName = new dataType[arraySize];

• Arrays in Java are declared using the syntax: arrayName = new dataType[arraySize];

• dataType[] arrayName = new dataType[];

• Arrays in Java are declared and initialized using the following syntax: dataType[] arrayName = new dataType[arraySize];

What is the difference between 'while' and 'do-while' loops in Java?

• The main difference is that the 'do-while' loop will always execute the code inside the loop at least once, regardless of the condition.

• In 'do-while' loop, the condition is checked at the beginning of the loop, while in 'while' loop, the condition is checked at the end of the loop.

• The 'while' loop can only be used for iterating over arrays, while the 'do-while' loop can be used for any type of iteration.

• The 'do-while' loop is more efficient than the 'while' loop in terms of memory usage.

Explain the 'for' loop in Java with an example.

• Example: for(int i=1; i<=5; i++){ System.out.println(i); }

• Example: for(int i=1; i<5; i++){ System.out.println(i); }

• Example: for(int i=0; i<5; i++){ System.out.println(i); }

• Example: for(int i=5; i>=1; i--){ System.out.println(i); }

What is the use of 'break' and 'continue' statements in Java?

• The 'break' statement is used to skip the current iteration of a loop, while the 'continue' statement is used to execute the loop only once.

• The 'break' statement is used to terminate the loop or switch statement, while the 'continue' statement is used to skip the current iteration of a loop.

• The 'break' statement is used to skip the current iteration of a loop, while the 'continue' statement is used to terminate the loop.

• The 'break' statement is used to execute the loop only once, while the 'continue' statement is used to terminate the loop.

How are strings represented in Java?

• Strings are represented as primitive data types in Java.

• Strings are represented as integers in Java.

• Strings are represented as objects of the class java.lang.String.

• Strings are represented as arrays of characters in Java.

Explain the concept of 'concatenation' in Java.

• Concatenation in Java refers to the process of converting a string to an integer

• Concatenation in Java is the process of combining two or more strings into a single string.

• Concatenation in Java is the process of sorting strings in alphabetical order

• Concatenation in Java involves separating a string into multiple substrings