Essential Internal Functions

So, before all, let's talk about some essential internal functions that are used in the language.

We will only talk about 4 functions here, but there are many more functions in the language to help you with your code. The 4 functions are: print, println, range and panic.

print(...) & println(...)

Both print and println functions are used to output content to the console. It is very useful if you want to see what is happening in your code.

Here is an example of how to use the print function:

print("Hello, World!")

The output is very straightforward:

Hello, World!

The println function is the same as the print function, but it adds a newline character at the end of the output. Here is an example:

println("Hello, World!")

The output is:

Hello, World!

So now, you may be confused, why? They look the same? Here is the answer. If we want to output 2 strings, e.g. 'Hello' and 'World', we can use the print function like this:

print("Hello")
print("World")

The output is:

HelloWorld

But if we use the println function like this:

println("Hello")
println("World")

The output is:

Hello
World

The difference is that the println function adds a newline character at the end of the output.

If you want to print a new line with print, you may use \n inside the string, but that's a bit more complicated. We'll talk about it later.

range(x)

The range function is used to create a range of numbers. It is very useful when you want to iterate over a list of numbers. The range(x) will create a range from 0 to x-1, in math we write it as $[0, x)$ (or $[0, x-1]$).

Here is an example of how to use the range function:

x = range(5)

Then x will be a list of numbers from 0 to 4, i.e., [0, 1, 2, 3, 4].

This will be very useful when you want to iterate over a list of numbers. We will talk about it later.

panic(err)

The panic(err) function is used to stop the program immediately. It is very useful when you want to stop the program when an error occurs.