CECS 130 EXAM 1

Data Type Description Declaration Example

Integer Floating point number Character Whole numbers, positive or negative All numbers, positive or negative, decimals and fractions Representations of integer values known as character codes To declare a constant (read only) value: const int x = 20; const float PI = 3.14; Can we do this? const int x; int x = float x = ; ; -3 , 0, 3 , 29 -0.35543 , 0.00, 554433.33281

char x =‘’ ; m, M, *

TYPE

bool char int short long float double

SIZE

1 byte 1 byte 4 bytes 2 bytes 4 bytes 4 bytes 8 bytes

VALUES

true (1) or false (0) ‘a’ to‘z’ , ‘A’ to ‘Z’, ‘0’ to ‘9’, space, tab, and so on -2,147,483,648 to 2,147,483,647 -32,768 to 32,767 -2,147,483,648 to 2,147,483,647 + - (1.2 x 10^-38 to 3.4 x 10^38) +- (2.3 x 10^-308 to -1.7 x 10^308)

} #include #include { main() printf(“\nC you later\n”); system(“pause”);

Serve to control program execution and functionality. Must end with a semicolon(;) with the exception of:     Comments: /* */ Preprocessor Directives: #include or #define Begin and end program identifiers: { } Function definition beginnings: main()

 Functions allow you to group program statements under one name  C and C++ are case-sensitive so main(), MAIN(), and Main() are all different functions.

 The main function is special because the values it returns are returned to the operating system  Most main functions in this course do not take or pass information to the operating system

     #include  Using a directive to include a header file stdio.h = standard input output header file stdlib.h = ‘system’ commands Iostream.h= Input/Output stream header library Math.h= The Math library header file

 Definition: Escape sequences are specially sequenced characters used to format output  \”  Ex: printf(“ \ “This is quoted text \ “ “);  \’  Ex: printf(“ \n A single quote looks like \’ \n”);  \* *\ Comment Block

     Character Integer Float (decimal) String Printf Format Tags: %c %d %f %s %[flags][width][.precision][length]specifier %[.precision]specifer -> %.2f

#include } int main() { int x; for ( x = 0; x < 10; x++ ){ printf( "%d\n", x ); } getchar();

}  int main() { printf (“%c %c \n", 'a', 65); printf ("%d %ld\n", 1977, 650000L); printf (" %10d \n", 1977); printf ("%010d \n", 1977); printf ("floats: %4.2f \n", 3.1416); printf ("%s \n", "A string"); return 0; }

printf (“%c %c \n", 'a', 65); printf ("%d %ld\n", 1977, 650000L); printf (" %10d \n", 1977); printf ("%010d \n", 1977); printf ("floats: %4.2f \n", 3.1416); printf ("%s \n", "A string"); aA 1977650000 1977 0000001977 3.14

A string  Can you create a tabular data using printf?

Example

printf(“%.1f”,3.123456); printf(“\n%.2f”,3.123456); printf(“\n%.3f”,3.123456); printf(“\n%.4f”,3.123456); printf(“\n%.5f”,3.123456); printf(“\n%.6f”,3.123456);

Printout

3.1

3.12

3.123

3.1235

3.12346

3.123456

#include { main() int iOperand1 = 0; int iOperand2 = 0; printf(“\n Enter first operand: “); scanf(“%d”, &iOperand1); printf(“\n Enter second operand: “); scanf(“%d”, &iOperand2); } printf(“The result is %d \n”, 24/(iOperand1 * iOperand2)+6/3);

Operator Description

* Multiplication / % + Division Modulus (remainder) Addition Subtraction

Order of Precedence Description

( ) Parentheses are evaluated first, from innermost to outermost *, /, % + , Evaluated second, from Left to Right Evaluated last, from Left to Right

#include { main() int x = 4; int y = 9; int result1, result2; result1 = y/x; result2 = y%x; } printf(“The result is %d.%d \n”, result1, 25*result2);

Operator

== != > < >= <=

Description

Equal to Not Equal Greater Than Less Than Greater Than or Equal to Less Than or Equal to

Order of Precedence Description

&& AND condition || OR condition

x++; ++x; x--; --x; Tells the function to use the current value of x and increment it by 1.

Increment the value of x by 1 and use the new value for calculations.

Tells the function to use the current value of x and decrease its value by 1.

Decrease the value of x by 1 and use the new value for calculations.

x=0; printf(“The Value of x is: %d”, x++); printf(“\n The Value of x is: %d”,++x); Would results in: The Value of x is: 0 The Value of x is: 2

Application of: += & -=

x += y; x -= y;

Equivalent Equation

x = x + y; x = x – y;

Do you know the answers to these?

 A. !( 1 || 0 )   B. !( 1 || 1 && 0 ) C. !( ( 1 || 0 ) && 0 )

 A. !( 1 || 0 ) ANSWER: 0  B. !( 1 || 1 && 0 ) ANSWER: 0 (AND is evaluated before OR)  C. !( ( 1 || 0 ) && 0 ) ANSWER: 1 (Parenthesis are useful)

 What’s the syntax of  While(Logical Condition){  }  Do{   } While(Logical Condition) What’s the difference between While and Do- While()?

 while ( condition ) { Code to execute while the condition is true }  do { } while ( condition );  Do{} while() executes code at least once!

  Use when the number of iterations is already known Syntax: for ( variable initialization; condition; variable increment/decrement) { Code to execute while the condition is true }

 Write a program using a FOR Loop to display all of the multiples of 5 from 0 to 100.

#include } int main() { int x; for ( x = 0; x < =20; x++ ) { printf( "%d\n", x*5 ); } getchar();

   Use to manipulate flow in loops What does a Break statement do when executed within a loop?

What does a Continue statement do when executed within a loop?

#include } main() { int x; for ( x = 10; x >5; x-- ) { if (x==7) break; } printf( “\n %d \n ”, x ); #include } main() { int x; for ( x = 10; x >5; x-- ) { if (x==7) continue; printf( “\n %d \n ”, x ); }

 Function Prototype Syntax return-type function_name ( arg_type arg1, ..., arg_type argN)  Function Prototypes tell you the data type returned by the function, the data type of parameters, how many parameters, and the order of parameters  Function definitions implement the function prototype  Where are function prototypes located in the program?

 Where do you find function definitions?

 Where are function prototypes located in the program?

 Answer: before the Main(){} Function!

 Function Definitions are self contained outside of the Main(){} function

#include int mult (int,int); int main() { int x; int y; printf( "Please input two numbers to be multiplied: " ); scanf( "%d", &x ); scanf( "%d", &y ); printf( "The product of your two numbers is %d\n", mult( x, y ) ); getchar(); } int mult (int a, int b) { return a * b; }

#include Void printReportHeader(); } { main() printReportHeader; } { void printReportHeader() printf(“\n Column1\tColumn2\tColumn3\tColumn4 \n”);

#include void printNumbers(); int iNumber; } main() { } int x; for(x=0, x<10,x++){ printf(“\n Enter a number:”); scanf(“%d”, &iNumber); printNumbers(); } { void printNumbers() printf(“\n Your number is: %d \n”, iNumber);

   Variable scope defines the life time of a variable Local Scope: defined within functions and loses scope after function is finished. Can reuse in other functions (ex. p.123) Global Scope: defined outside of functions and can be accessed by multiple functions