Question

→ What are the decisions you have to make when programming computer?

Answer 1

We need to make some decisions when we programming a computer. For example, if a condition X satisfy then Y execute
otherwise Z execute.

if x then
Y
else
Z

Suppose, we want to find out maximum of two numbers A and B. Now, we need to make decision that if A is greater than B, then A is a maximum number, otherwise B is maximum.

if A > B then
A is maximum
else
B is maximum

There may have more than one decisions, then we combine these decisions using AND or OR operators.
Suppose, we want to find out letter grade of a student from average grade. We can use following decisions:

if average>=90 AND average<=100 then
grade = A
else if average>=80 then
grade = B
else if average>=70 then
grade = C
else if average>=60 then
grade = D
else
grade = F

When average grade greater or equal to 90 and less than or equal to 100 then letter grade is A. So on..
Therefore we need to make decisions for which condition the letter grade have achieved.

In C/C++/Java programming languages some decision making statements available:
Simple if statement
if-else-if statement (ladder if)
nested if statement
switch statement