Computer Fundamentals (Final Term)

#include

Instructs the C preprocessor to find the text file “stdio.h” or the standard input and output.

Comments (/* */)

May span any number of lines

Main

The most important. It defines the point at which your program starts to execute.

“{“

Means begin in Braces

“}”

Means end in Braces

“//”

A comment that only spans 1 line

Printf

Standard way of producing output.

“\n”

How C handles new lines. or “Enter”

Return

Causes the value to be passed back to the operating stem.

Return 0;

Means that the code is successful.

Return 1:

Means that the code failed.

True

Statements in the body are ended with semicolons “;”

True

Indention is ignored by the compiler (but it is important in programming)

True

C is case sensitive

True

Strings are placed in double quotes (“ “)

\t

Means tab or space

Data Type

Indicates the type of data that can be represented in the value of the data element.

int: integer

A whole number

float: floating point value

A number with a fractional part

double

A double-precision floating point value.

char (enclosed in ‘ ‘)

A single character

void

Valueless special purpose type

%d

int: integer

%f

float: floating point value

%lf

double

%c

char

%s

void

True

Local Variables must be declared after the “{“

True

Global Variables must be declared after the directives

True

Valid characters are letters, digits, and “__”

True

First character cannot be a digit

True

There are 31 character for local variables

True

There are 6 global variables

True

Name must relevant to its value

Constant

Retains a constant value throughout the execution of the program

Scanf

Gets an input value from the user

True

double r;

const double pi = 3.14159;

double a;

printf("\nEnter Radius Value:\t");

scanf("%lf", &r);

without the “&” the value will retain the generated random number during the declaration.

Operators

Used to perform operations on variables and values

Arithmetic Operators

Used to perform common mathematical operations

+

Addition

-

Subtraction

*

Multiplication

/

Division

%

Modulus

++

Increment

--

Decrement

Increment

Increases the value of an operand by 1

Decrement

Decreases the value of an operand by 1

Unary Operators

Only operates on a single operand

Assignment Operators

Used to assign values to variables

Comparison Operators

Compare two values (or variables)

Comparison Operators

Helps to find answers and make decisions

Comparison Operators

Return Value is either 1 for true and 0 for false. These are also known as “Booelan Values”

==

Equal to

!=

Not equal to

>

Greater than

<

Less than

>=

Greater than or Equal to

<=

Less than or equal to

Logical Operators

Can test true or false. Used to determine the logic between variables/values

&&

Logical and — returns true if both are true

||

Logical or — returns true if one is true

!

Logical not — reverse, returns false is result is true

Operator Precedence

Determines the grouping of terms in an expression and decide how an expression is evaluated

<math.h>

Contains methods for performing mathematical operations

ceil (number)

Rounds up the given number

floor (number)

Rounds down the given number

sqrt (number)

Returns the square of the given number

pow (base, exponent)

Returns the power of the given number

abs (number)

Returns the absolute value of the given number

Type Casting

Converting one datatype into another

Implicit Type Casting

Converts the datatype to any variable without using the actual value.

Explicit Type Casting

Force the conversion between data types.

Advantages of Type Casting

• makes the program very lightweight

• type representation and hierarchies

• helps programmers to convert one data type to another type