411 REFERENCE · Wikibooks
An Introduction to Dragon/Lessons/Control Structures
Reference material by Wikibooks contributors. This retains its source identity and is not 411 news reporting.
Control Structures
In this chapter we are going to learn about the control structures provided by
the Dragon programming language.
Branching
If Statement
Syntax:
if(Expression)
{
Block of statements
}
else if(Expression)
{
Block of statements
}
else {
Block of statements
}
Example:
select "types"
select "graphic"
nOption = int(prompt("1) Say Hello \n2) About")
if nOption == 1
{
name = prompt("Enter your name: ")
showln "Hello " + name
}
else if nOption == 2
{
showln "Sample : using if statement"
}
else
{
showln "bad option..."
}
Looping
While Loop
Syntax:
while(Expression)
{
Block of statements
}
For Loop
Syntax:
for (identifier=initialize value, terminating expression, step expression)
{
Block of statements
}
Example:
// print numbers from 1 to 10
for (x = 1, x <= 10, x++)
{
showln x
}
Foreach Loop
Syntax:
for (identifier : List/String)
{
Block of statements
}
Example:
aList = [1,2,3,4] //create list contains numbers from 1 to 10
for x : aList
{
showln x // print numbers from 1 to 10
}
Do While Loop
Syntax:
do {
body
} while (condition)
Example:
x = 1
do {
showln x
x++
}
while (x <= 10)
Dragon programming language