Use your preferred compiler to investigate the programming exercises below. This laboratory concerns  the  use  of relational  and  logical  operators  together  with  branching  flow  control statements if/else and switch and looping.

Logical Operators

Here is a table of the common logical operators you have learned about in your lectures.

Give equivalent expressions for the following logical expressions without negation

Example

!(a<5 || a>10) is equivalent to a>=5 && a<=10

Hint: Apply operator precedence rules given during lectures.

For the following declarations complete the table by correctly parenthesizing the expression and then finding the value:

int a=1, b=2,c=3;

double x=1.0

Write a C program to print the values on the screen to see if your answers are correct.

What gets printed by the following program?

char c=’A’;

int i=5, j=10;

printf(“%d\t%d\t%d\n”,!c, !!c, !!!c);

printf(“%d\t%d\t%d\n”,-!i, !-i, !-i-!j);

printf(“%d\t%d\t%d\n”,!(6*j+i-c), !i-5, !j- 10);

Note: The ASCII code for ‘A’ is 65. Be careful about following the precedence rules!

In each case below, construct a logic expression to express the following conditions and then write a program to test your expression:

.    Determine if an int variable number is equal to or greater than 1 but smaller than 9.

.    Determine is a char variable ch is not the value q or k.

.    Determine if an int variable number is between 1 and 9 but is not 5.

.    Determine if an int variable number is not between 1 and 9

Example:

number is 5 or 10

Solution

number ==5 || number ==10

The if, if-else and switch Statements

What gets printed by the following programs? Do it on paper first and then use the computer.

Program 1

int i=7, j=2;

if(i==1)

if(j==2)

printf(“%d\n”,i=i+j);

printf(“%d\n”,i=i-j);

printf(“%d\n”,i);

Program 2

What gets printed when n=101 or n=10

#define LIMIT 100

main(){

intn;

printf (“Enter an integer: ”);

scanf(“%d”, &n);

switch (n){

case LIMIT- 1 :           printf (“slightly less”); break;

case LIMIT     :           printf (“exact”); break;

case LIMIT+1 :          printf (“slightly high”); break;

default             :           printf (“too far”); break;

}

}

The mathematical operation min(x,y) can be represented by the conditional expression: z=(x<y) ? x : y;

Or

if(x<y)

z=x;

else

z=y;

Write your own expression (in either format) to define the mathematical operation min(x,y,z).

Write a program to take the depth (in kilometers) inside the earth as input data. The program should use this information to compute and display the temperature at this depth in degrees Celsius and degrees Fahrenheit. The relevant formulae are:

Celsius temperature at depth in km formula:

Celsius = 10 x depth + 20

Celsius to Fahrenheit conversion formula:

Fahrenheit = 1.8 x Celsius + 32

Write a program that computes the square root of a given real number. The program should let its user know  that  negative  numbers  are  not  accepted.  Its  execution  should  look  like  the following:

Give anon negative number:  2

Its square root is 1.4142214

Give anon negative number: - 1

This is a negative number; please provide anon negative one!

Hint: Include the math.h header file and use the function sqrt() to calculate the square root.

Looping

The following exercises concern the use of loops: while, do while, for; together with relational and logical operators and branching flow control statements if/else or switch.

Write two programs, first using a while loop and second using a for loop to print the numbers from 1 to 10 and their squares (See the example output below):

Write a program using two nested for loops (see your lecture 4 notes) to print the following

triangle

*

**

***

****

*****

Note: don’t use multiple printf statements or one long printf statement, try to achieve it with loops.