The sequence control construct is present in all programs from the most simple to the extremely complex. One command is carried out at a time from the beginning to the end of the program in the correct order.

Example algorithm:

Get Number1
Get Number2
Calculate Total as Number1 + Number2
Display ‘The total is ‘ Total

Example code:

var Number1 = 0;
var Number2 = 0;
var Total = 0;

Number1 = prompt('Enter the first number:');
Number1 = parseInt(Number1);

Number2 = prompt('Enter the second number:');
Number2 = parseInt(Number2);

Total = Number1 + Number2;

alert ('The total is ' + Total);

The code shown will be executed from top to bottom one command at a time. In the example shown there are three variables declared and used. The program then follows the idea of input, process and output.

Note: Do not worry about what each line of code does at the moment because that it what we are going to look at next.

Next: Input