Defining Sequence or Sequential Structure (scheduling)

In programming, the sequence structure is a type of control structure. Also called sequential structure.

The sequence structure refers to the order of execution of instructions that is done sequentially, that is, one instruction after the other.

The instructions follow each other in such a way that the result of the previous one can affect the next one.

It is the basic order of execution in programming languages, and its order is from top to bottom.

It is the basis for writing algorithms. Let’s look at an example in pseudocode:

to := 1
b := 7
r := a + b
show(r)
r := a
show(r)

This will display as a result:
8 (first call to show function)
1 (second call to show function)

As you can see, each statement affects the following in a sequential order of execution from top to bottom, executing one line at a time.

Sequence structure: statement 1 is performed, then statement 2 … until statement n

Within a sequence structure we can use other structures that «break» it with another behavior. The most typical are: selection structure, and repetition structure.

In turn, within each of these selection and repetition structures there are sequence structures as well.