Page 106 - Trackpad_V5_Book 8
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As you know that a computer program is a set of instructions given to the computer to perform
a specific task. These individual instructions are known as statements. All the statements are
executed sequentially one after the other as they appear in a program but in some situations,
we have to change the order of execution of the program based on certain conditions. In such
situations, we use control statements to control or change the flow of execution.
CONTROL STRUCTURE
A control structure is a programming construct which affects the flow of the execution of a
program. Various types of control structures provided by Python are shown below:
Control Structure
Sequential Statements Selection Statements Iterative Statements
SEQUENTIAL STATEMENTS
The statements that are executed in sequential order, i.e., one after the other without any jumps,
are called sequential statements. A sequential structure is also known as a straight line path.
Statement 1
Statement 2
Statement 3
SELECTION STATEMENTS
Some problems cannot be solved by performing a set of ordered steps as seen in sequential
execution. When programmers are required to execute a particular set of statements depending
upon a particular test condition, a selection or decision making statement is required. Python
provides the following selection statements:
(i) if statement (ii) if-else (iii) if-elif-else statement
THE if STATEMENT
The if statement is a decision-making statement which is used to control the flow of execution of
statements.
104 Pro (Ver. 5.0)-VIII

