CSC133 Intro to CS Using C++

Vocabulary

algorithm

a step by step plan for solving a particular problem.

memory

the component in a computer that holds a program while it is executing and all of the data that is being used. Memory is made up of millions of cells; each cell is called a byte (composed of 8 bits) and is large enough to hold one character.

address (memory address)

each cell in memory has an address, which is used to refer to that cell. To get data from memory, a program gives the address of the cell that holds the data. To put data into memory, a program gives the address of the cell which will hold the data. In higher level languages, programmers use identifiers instead of addresses to access memory.

variable

a name for a memory location that can hold a value. The value of a variable can be changed during execution of the program.

type (data type)

defines a set of values with similar characteristics and the operations that may be performed on those values. Some examples of types are are int, float, and char. Some operations defined for int and float are addition and subtraction.

identifier

name for some construct within a program, such as the name for a variable, constant, or function.

constant (literal)

a specific value, such as the number 15, the number 22.9, the character 'a', or the string "The answer is"

named constant

identifier that is given a constant value. The value of the identifier cannot be changed during execution of the program. Example:

		const float taxrate=0.22;

declaration

a statement that defines a variable or named constant by specifying the name and type for the variable or constant. The declaration causes the compiler to allocate memory for the variable or constant, and associates the name and type with that memory location. Example:

		int length;
		char letter;
		float price;

initialization

the assignment of a value to a variable or named constant at the time of declaration. If a variable is not initialized then it contains garbage (some random, unpredictable value) until a value is stored in the variable by an assignment statement or cin statement. Example:

		int sum = 0;
		const float pi = 3.14159;

operator

a symbol or identifier that represents an action, such as + (for addition) and * (for multiplication).

operand

the value that an operator acts upon. For example, in num * 15, the operator is * and the operands are num and 15.

expression

any combination of variables, constants, operators, and function calls that can be evaluated to yield a result

arithmetic expression

an expression that contains arithmetic operators and which evaluates to a number.

logical expression (boolean expression)

an expression that contains logical operators and which evaluates to either true (1) or false (0).

assignment statement

statement that stores a new value into the variable on the left side of the assignment operator (=). The new value can come from a variable or constant, an arithmetic expression, or a function call. Examples:

		count = 0;
		area = length * width;
		tax = taxOwed(income, taxrate);