What is the difference between a++ and ++a in Java?
Both increase a by 1. a++ is postfix: it hands the current value to the expression and then increases a. ++a is prefix: it increases a first and hands over the new value. With a = 5, b = a++ makes b 5, while b = ++a makes b 6. In both cases a ends as 6.
How do you solve a++ + ++a in Java?
Go left to right. With a = 5, a++ hands over 5 and a becomes 6; then ++a makes a 7 and hands over 7. The sum is 5 + 7 = 12 and a ends at 7. Write the value used and the new value of a for each operand before adding anything.
What is the precedence of operators in Java for ICSE?
From high to low: brackets, postfix ++ and --, prefix ++ and --, unary minus and !, then * / %, then + -, then the comparisons less than and greater than, then == and !=, then &&, then ||, then the ternary operator, and finally the assignment operators. Brackets always override the order.
What is the ternary operator in Java with an example?
It is the conditional operator: a condition, a question mark, a value for true, a colon and a value for false. Java returns the first value when the condition is true and the second otherwise. For example, a one-line statement can store "even" or "odd" in a String depending on whether n % 2 == 0. It is the only Java operator with three operands.
How do you convert if-else to the ternary operator?
Check that both branches assign a value to the same variable. Then write that variable and =, followed by the condition, a question mark, the value from the if branch, a colon, and the value from the else branch, ending with one semicolon. The two assignments and the if-else keywords disappear, and the line does exactly the same job.
What is the difference between = and == in Java?
= is the assignment operator: it stores the value on its right in the variable on its left. == is a relational operator: it compares two values and gives true or false. Writing if (x = 5) with an int x does not compile, because the condition of an if must be boolean.
What is the difference between / and % in Java?
/ gives the quotient and % gives the remainder. With two ints, 17 / 5 is 3, because the fraction is dropped, and 17 % 5 is 2. With a negative left operand the remainder is negative: -17 % 5 is -2. The pair is used in every digit-extraction program.
What are unary, binary and ternary operators?
They are grouped by how many operands they take. Unary operators take one, such as ++, --, unary minus and !. Binary operators take two, such as + - * / %, == and !=, && and ||. The ternary conditional operator takes three: a condition and two values.
Does x += 1 do the same as x = x + 1?
For an int x, yes. The difference shows with smaller types: for a short or char variable, x += 1 compiles because compound operators cast the result back automatically, while x = x + 1 does not compile, because x + 1 is an int and needs an explicit cast.
Do you teach operators in the live ICSE classes?
Yes. Operators are revised early in the year and then practised every week through timed Tuesday sets at 5:30 PM IST, with every expression run in BlueJ on a shared screen. They also appear inside the Wednesday programs and the board-style mock tests. Personalised one to one classes are available at a time the family chooses.
