PHP:Flags with Repeats Tutorial

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We can repeat a statement or block of statements with a for loop. The simplest for loops take the following form:

The control variable i takes every value 0,1,2..9 in turn. We can use the value of i inside the loop if required.


The flag of Bahrain has a five irregular pentagons on a red background.

Each pentagon can be represented by five points such as (0,0), (64,0) (100,15) (64,31) and (0,31).

Flag of Bahrain

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Consider the neighbouring state Qatar.

  • 9 pillars, each pillar is 17 pixels below the previous.
  • The five coordinates of the top pillar are (0,0) (84,0) (125,9) (84,17), (0,17)
  • Use RGB(128,0,0) for the less jaunty red.

Flag of Qatar

The need for a loop becomes even more obvious for this flag.

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European Union

Flag of European Union

We need the trigonometry functions cos and sin to draw flags in a circle.

  • There are 12 stars
  • The flag is 250 by 180
  • The stars centers are 64 from the center
  • The coordinates at 30o from the x-axis (East) are 64*cos(30), 64*sin(30).
  • Each star has radius 12.5

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