random important facts

Question 1

java precedence rules (high to low)

Answer 1

parentheses:( )
unary ops: +x -x ++x –-x x++ x-- !x
multiply/divide: * / %
add/subtract: + -
comparisons: < > <= >=
equality: == !=
logical and: &amp;&amp; 
logical or: ||
assignments:= += *= /= %= (these are right to left associative)

Question 2

short-circuiting

Answer 2

As soon as Java knows an answer, it quits evaluating the expression (regardless of what the 2nd expression is)

Question 3

is (++x==0) executed?

int x = 0, y = 1;
if ((y > 1) && (++x == 0)){
}

Answer 3

no, because (y>1) is false, java stops evaluating the expression, before it reaches the 2nd part.

Question 4

break

Answer 4

allows you to exist immediately from a loop
(while, do-while, for)

(only use break when loop condition is always true)

Question 5

continue

Answer 5

jumps to the bottom of the loop immediately ( } ), and starts the next iteration

Question 6

math.

Answer 6

math. provides static services

methods: math.add, math.ceil, math.floor, math.pow, math.random (values btwn 0-1

Question 7

switch statement

Answer 7

replacement for cascading if-else statements (if tested expression is an integer, string, or enum)

Question 8

switch statement code

Answer 8

switch
(〈control-expression〉) { 
case〈case-label-1〉:
〈statement-sequence-1〉
break; 
case〈case-label-2〉:
〈statement-sequence-2〉
break; 
…
case〈case-label-n〉:
〈statement-sequence-n〉
break; 
default:〈default-statement-sequence〉
break; 
}

Question 9

control expression

Answer 9

can be of one of the following types:

char, int, short, byte, String, enum

Question 10

“break” statement

Answer 10

jumps out of the switch statement. Otherwise control
flow just “falls through” into the next case
(falling though
behavior is handy, because it allows you to combine cases)

Question 11

floating point

Answer 11

you can never use == to compare floating points. Check if 2 numbers are within a certain tolerance of each other:
Math.abs((3.9-3.8) - 0.1)