Lec 5

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if statements

if else statements

Syntax if (condition) { //code } //rest of program

Syntax if (condition) { //code } else { //code }

What gets printed? i=10; j=5; z=2; i=10; j=5; z=2; if(i == 10) { if(i == 10) if(i > j) if(i > j) z *= 2; z *= 2; else } z *= 4; else { System.out.println(“z=“ + z); z *= 4; } System.out.println(“z=“ + z);

A) z=2 z=2

B) z=4 C) z=4 z=4 z=8

D)z=2 z=8

E)z=8 C.E.

if – else-if

if else-if syntax if (condition) { //code } else if (condition) { //code } else if (condition) { //code } else { //code }

Conditions • <, >, <=, >=, ==, != – Note: =>, =<, =! Will give compiler errors

• = is not the same as ==

Order of operations ()

Compute anything inside 1st

! pre ++ -- (e.g. ++var, --var)

Left to right

Type cast

Left to right

* / %

Left to right

+ -

Left to right

< <= > >=

Left to right

== !=

Left to right

&& ||

Left to right

=

assignment

post ++ -- (e.g. var++, var--)

Left to right

()

! pre ++ -- (e.g. ++var, --var) Type cast * / %

What’s the value of exp1?

+ < <= > >=

int a = int b = int c = boolean a) true

7; -1; 2; exp1 = !(a + b * c >= a + c * b); b) false

c) C.E.

d) False

== != && || = post ++ -- (e.g. var++, var--)

e) B and D are the same

Logical Operators a && b -- a AND b. both must be true a || b – a OR b. One or both must be true !a – NOT a. flips a

Which of these evaluates to true int i =10; char c=‘A’; a) i > 10 || i < 20 b) !(i > 10 && i < 20) c) i*7+c/2 > 34 || c == ‘A’ d) a and c e) All of the above