Lecture 3 and 4 - Operators and conditional statements Loops

Question 1

How many types of operators are there in java ?

Answer 1

Arithmetic operators (+, -, *, /, %) double a = 7/2; //equals to 3.0, instead of 3.5

Assignment operators (+=, -=, *=, /=, %=, <<=, >>=, &amp;=,...)
x += 2; //equivalent to: x = x + 2;

Relational operators (==, !=, >=, <=, >,

Question 2

Types of incremental and decremental operators

Answer 2

Postfix (x++, x–): The result is the value of x before the operators

Prefix (++x, –x): The result is the value of x after the operators

Question 3

Bitwise and shift operators:

Answer 3

∼x \_\_\_\_Bitwise compliment of x
x & y \_\_ Bitwise AND of x and y
x | y \_\_\_Bitwise OR of x and y
x ∧ y \_\_Bitwise XOR of x and y
x << k _Left shift
x >> k _Right shift
x >>> k Unsigned right shift

Question 4

Ternary operator:

Answer 4

The ternary operator can replace a if-else statement

Syntax:
condition ? exprTrue : exprFalse;

ex. min = (a<b></b>

Question 5

What is a for loop used for ?

Answer 5

A for loop can be used to execute a block of statements repeatedly when the repeating time is known ex.
for(initialization; condition; incr/decr){
}

Question 6

Example of for each in java ?

Answer 6

int []numArray = {7,2,6,0};
for(int i:numArray){
System.out.println(“number is: “ + i);
}

Question 7

Do while and while loop difference :

Answer 7

while loop might not ever run. do-while loop runs at least once.

Question 8

What does continue do ?

Answer 8

The continue statement skips the current iteration of a loop.

Only skips the innermost enclosing loop of the statement.