AP CSA - Fall Semester Review

public class ProgramName

public void main(String[] arg)

role of ‘main’ in second line

System.out.println(“”);

case sensitive language; missing character (ex: ; ( { )

displays “hello” instead of “HELLO”; mathematical error by programmer

occurs during execution; ex: divide by 0, out of bounds access of an array

may include: letters, numbers, _, $; may not start w/ number; no spaces

used in editor; MyName.java

used in compiler; MyName.class

used in interpret (JVM); code is translated + executed

checks for syntax errors; creates byte code, if there are no errors

displays argument

displays argument, then CRLF

carriage return + line feed; new line

implies printing output

implies receiving user input

escape sequence; new line

escape sequence; prints one slash

escape sequence; prints one double quote

4 data types: byte, short, int, long; number with no decimals

2 data types: float, double; number with decimals

1 data type; true or false

reference data type; saves reference to base16 memory address

using ‘+’ to add strings

declare constant version of variable

add by number after ‘=’

subtract by number after ‘=’

divide by number after ‘=’

multiply by number after ‘=’

divide by number after ‘=’; return remainder

division between two integers; returns no remainder or decimals

division with at least one real number; returns decimals

division between two integers; returns remainder

shortcut type; math sign then ‘=’ sign

shortcut type; variable and two of math sign

adds one to x

subtracts one from x

used when declaring variable; do not use twice

hi55

hi10

Math.pow(int x, int n);

Math.sqrt(int x);

.substring(int begIndex); 

.substring(int begIndex, int endIndex);
	# does not include end Index

(“Hello World”).substring(4, 10);

returns string length; starts with 1

returns position of first occurrence of str; returns -1 if not found

returns character at a specified string

(“Hello World”).charAt(4);

executed if condition (placed in parentheses) is true; no semicolon at end; expects one line of following code, use { } for more

if (5 == 5)
	return(“hi!”);

less than

less than or equal to

greater than

greater than or equal to

equal to, for logic

compares one String to another; returns boolean

not equal to, for logic

for loop; condition will return true while loop continues; index can be manipulated in various ways; standard form

best for loop for iteration through arrayList which you will be removing items from

enhanced for loop; does not provide index or easily update item values

loop that iterates until condition is false; no provided index; condition must be in parentheses; expects one line of following code, use { } for more

provides a random double in [0.0, 1.0); to manipulate, add, divide, and Integer type casting

returns a number between 4 and 14 (inclusive)

first line in method definition; includes visibility, return type, method name, and parameters

method header return type; no return

specifies data type of returned values

data type needs to be specified (ex: (int age))

returns length of an array

provides element at index i of array

initialize int array with default values

initialize String array with pre-set values

default String value

default int value

default boolean value

adds an element obj to the end of ArrayList

adds an element obj at index of ArrayList

changes element at index of ArrayList to obj

removes an element at index of ArrayList

accesses element at index of ArrayList; used to print element

returns the size of ArrayList

initialize empty ArrayList; can contain any object type

int x = 0;

for (int num : arrList)
	x += num;

return x;

int x = 0;

for (int num : arrList)
	if (num == condition)
		x+= 1;

return x;

for (int i = 0; i < arrList.size(); i++)

	if (arrList.get(i) == condition)
		return i;

return -1;

for (int i = arrList.size() - 1; i >= 0; i--)
	if (arrList.get(i) == condition)
		arrList.remove(i);

int x = nums.get(0);

for (int num : nums)
	if (num < x)
		x = num;

return x;

int x = nums.get(0);

for (int num : nums)
	if (num > x)
		x = num;

return x;