WGU D278 Study Guide Notes with Complete Verified Solutions.
WHAT IS THE PURPOSE OF A VARIABLE?
A NAMED ITEM USED TO HOLD A VALUE
HOW DO YOU SAVE A VALUE TO A VARIABLE?
WITH AN ASSIGNMENT STATEMENT, EG X = X + 1
WHAT IS A PROGRAMMING EXPRESSION?
A NUMBER, VARIABLE NAME, OR SIMPLE CALCULATION; A COMBINATION OF
ITEMS THAT EVALUATES TO A VALUE
EG X + 1
WHAT IS AN IDENTIFIER?
A NAME CREATED FOR AN ITEM LIKE A VARIABLE OR FUNCTION
WHAT CONSTITUTES A VALID IDENTIFIER?
● BE A SEQUENCE OF LETTERS (a-z, A-Z), UNDERSCORES (_) AND
DIGITS (0-9)
● START WITH A LETTER
WHAT IS A LITERAL?
A SPECIFIC VALUE IN CODE
WHAT IS AN OPERATOR?
SYMBOLS THAT PERFORM CALCULATIONS, + - * /
WHAT PRECEDENCE RULES DOES PROGRAMMING USE?
● ITEMS IN PARENTHESES ARE EVALUATED FIRST
● THEN THE MINUS OPERATOR
● */
● +-
● LEFT TO RIGHT
, HOW DOES AN INTEGER DIFFER FROM A FLOAT?
INTEGERS ARE WHOLE NUMBERS, FLOATS HAVE DECIMALS
WHAT HAPPENS IF YOU DIVIDE TWO INTEGERS? A INTEGER AND
FLOAT? WHAT HAPPENS IF YOU DIVIDE A NONZERO FLOATING
POINT NUMBER BY ZERO?
● DIVIND INTEGERS DROPS ANY DECIMAL, EG 2.7 TURNS INTO 2,
ANY ABSOLUTE VALUE LESS THAN 1 BECOMES 0
● DIVING AN INTEGER AND FLOAT RESULTS IN A FLOAT
● DIVIDE A NONZERO FLOAT BY ZERO IS EITHER POSITIVE OR
NEGATIVE INFINITY
HOW DO YOU CONVERT AN ITEM’S TYPE?
● FOR ASSIGNMENTS, RIGHT SIDE TYPE IS CONVERTED TO LEFT
SIDE TYPE
WHAT DOES THE MODULO OPERATOR DO?
% EVALUATES THE REMAINDER, EG 23 % 10 = 3
WHAT IS THE DIFFERENCE IN A VARIABLE AND A CONSTANT?
THE VALUE OF A CONSTANT CANNOT CHANGE, WHILE A VARIABLE’S VALUE CAN
CHANGE
HOW DOES AN ARRAY WORK?
AN ORDERED LIST OF ITEMS OF A GIVEN DATA TYPE, LIKE AN ARRAY OF INTEGERS
OR AN ARRAY OF FLOATS
WHAT DOES INDEX REFERENCE?
WHAT IS THE PURPOSE OF EACH DIFFERENT DATA TYPE?
● INTEGER – TYPICALLY USED FOR VALUES THAT ARE COUNTED
● FLOAT – USED FOR MEASURED VALUES
● ARRAY – STORING LISTS OF DATA TYPES
WHAT IS THE PURPOSE OF A VARIABLE?
A NAMED ITEM USED TO HOLD A VALUE
HOW DO YOU SAVE A VALUE TO A VARIABLE?
WITH AN ASSIGNMENT STATEMENT, EG X = X + 1
WHAT IS A PROGRAMMING EXPRESSION?
A NUMBER, VARIABLE NAME, OR SIMPLE CALCULATION; A COMBINATION OF
ITEMS THAT EVALUATES TO A VALUE
EG X + 1
WHAT IS AN IDENTIFIER?
A NAME CREATED FOR AN ITEM LIKE A VARIABLE OR FUNCTION
WHAT CONSTITUTES A VALID IDENTIFIER?
● BE A SEQUENCE OF LETTERS (a-z, A-Z), UNDERSCORES (_) AND
DIGITS (0-9)
● START WITH A LETTER
WHAT IS A LITERAL?
A SPECIFIC VALUE IN CODE
WHAT IS AN OPERATOR?
SYMBOLS THAT PERFORM CALCULATIONS, + - * /
WHAT PRECEDENCE RULES DOES PROGRAMMING USE?
● ITEMS IN PARENTHESES ARE EVALUATED FIRST
● THEN THE MINUS OPERATOR
● */
● +-
● LEFT TO RIGHT
, HOW DOES AN INTEGER DIFFER FROM A FLOAT?
INTEGERS ARE WHOLE NUMBERS, FLOATS HAVE DECIMALS
WHAT HAPPENS IF YOU DIVIDE TWO INTEGERS? A INTEGER AND
FLOAT? WHAT HAPPENS IF YOU DIVIDE A NONZERO FLOATING
POINT NUMBER BY ZERO?
● DIVIND INTEGERS DROPS ANY DECIMAL, EG 2.7 TURNS INTO 2,
ANY ABSOLUTE VALUE LESS THAN 1 BECOMES 0
● DIVING AN INTEGER AND FLOAT RESULTS IN A FLOAT
● DIVIDE A NONZERO FLOAT BY ZERO IS EITHER POSITIVE OR
NEGATIVE INFINITY
HOW DO YOU CONVERT AN ITEM’S TYPE?
● FOR ASSIGNMENTS, RIGHT SIDE TYPE IS CONVERTED TO LEFT
SIDE TYPE
WHAT DOES THE MODULO OPERATOR DO?
% EVALUATES THE REMAINDER, EG 23 % 10 = 3
WHAT IS THE DIFFERENCE IN A VARIABLE AND A CONSTANT?
THE VALUE OF A CONSTANT CANNOT CHANGE, WHILE A VARIABLE’S VALUE CAN
CHANGE
HOW DOES AN ARRAY WORK?
AN ORDERED LIST OF ITEMS OF A GIVEN DATA TYPE, LIKE AN ARRAY OF INTEGERS
OR AN ARRAY OF FLOATS
WHAT DOES INDEX REFERENCE?
WHAT IS THE PURPOSE OF EACH DIFFERENT DATA TYPE?
● INTEGER – TYPICALLY USED FOR VALUES THAT ARE COUNTED
● FLOAT – USED FOR MEASURED VALUES
● ARRAY – STORING LISTS OF DATA TYPES
