To understand better the need for compilation, consider the following analogy.

 

Suppose you were to give driving instructions on how to get somewhere. If you were giving them to a human, these instruction might look like:

 

Leave downtown heading east.

As soon as you see the city limits sign turn right

Drive until you see a MacDonalds

Take the first major roundabout heading north

etc…

 

The above is the equivalent of macro code, rich and full-featured; each instruction requires detailed analysis.

 

Now suppose you were to build a device that would drive your car automatically, by following a sequence of instructions. Obviously you would not want to feed the above type of instructions into it. The type of instructions you would feed to a car would be something like:

 

Engine ON.

Shift into gear.

Accelerate to 50 km/h

Drive 5.5 km

Slowdown to 10 km/h

Turn right

Accelerate to 50 km/h

Drive 10 km

etc…

 

Note that this "car code" contains a lot fewer different instructions, and they are a lot less open to interpretation.

 

That is the equivalent of compiled code. The compiler translates the human language instructions (Macros) into instructions adapted to the computer.

 

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Topic 125001, last updated on 22-Apr-2020