Introduction to Programming Language

1. Introduction to Programming
Language

2. What’s the program?
• It contains a list of ingredients (called
variables) and a list of directions (called
statements) that tell the computer what to do
with the variables. The variables can represent
numeric data, text, or graphical images.

3. What’s the programming language?
• A programming language is a translator
between human and computer.
• It translates the human languages into
machine code so that a computer can
understand and run it.

4. Steps of writing a program
1. Read the problem.
2. Write an algorithm (Pseudocode) to solve the
problem.
3. Draw a flow chart for the program.
4. Choose a programming language.
5. Convert the algorithm into the programming
language.

5. Example 1
• Write an algorithm to calculate the area of the
square.

6. Pseudocode
1. Input the length.
2. area = length*length.
3. Print area

7. Flow chart Symbols
Terminator
Start / Stop Data I/O Process
No Decision Yes Flow line
Connector

8. Flow chart
Start
1. Input the length.
Input L
2. area = length*length.
3. Print area Area = L*L
Print
Area
Stop

9. Example 2
• Write an algorithm to print the maximum
number between three numbers (a, b, c).

10. Pseudocode
1. Read a, b, c.
2. if a>b
if a>c
print a
else
print c
else
if b>c
print b
else
print c