Shulou(Shulou.com)06/02 Report--

This article introduces the relevant knowledge of "how to use functions in Lua". In the operation process of actual cases, many people will encounter such difficulties. Next, let Xiaobian lead you to learn how to deal with these situations! I hope you can read carefully and learn something!

1. The use of functions

Example e02.lua

-- functions function pythagorean(a, b) local c2 = a^2 + b^2 return sqrt(c2) end print(pythagorean(3,4))

operation results

5

procedural notes

In Lua, functions are defined in the following format:

function name (parameter)

...

end

Unlike Pascal, end doesn't need to be paired with begin, just end after the function ends.

The function of this example is to find the hypotenuse length of a given right triangle. parameters a and b represent the length of a right angle, respectively.

A local variable is defined inside the function to store the square of the hypotenuse. Same as C, defined in function generation

Code is not executed directly, only when called by the main program.

Local means defining a local variable, if not local just means c2 is a global variable, local scope

The key is the key to the success of the project. end, while ... end etc. global variables

Scope is the entire program.

2. loop statement

e03.lua

-- Loops for i=1,5 do print("i is now " .. i) end

operation results

i is now 1

i is now 2

i is now 3

i is now 4

i is now 5

procedural notes

Here we use the for statement

for variable = parameter1, parameter2, parameter3 do

loop body

end

The variable will change from parameter 1 to parameter 2 in step 3

For example:

for i=1,f(x) do print(i) end

for i=10,1,-1 do print(i) end

print("i is now ") In i), we used.., This is used to concatenate two strings,

I don't know if you got it right.

Although i is an integer, Lua is automatically converted to string when processing, so we don't have to worry about it.

3. conditional branch statement

e04.lua

-- Loops and conditionals for i=1,5 do print("i is now " .. i) if i < 2 then print("small") elseif i < 4 then print("medium") else print("big") end end

operation results

i is now 1

small

i is now 2

medium

i is now 3

medium

i is now 4

big

i is now 5

big

procedural notes

If else usage is relatively simple, similar to C language, but here it should be noted that the whole if only needs an end,

Even if you use multiple elseif, it's an end.

for example

If op == "+" then r = a + b elseif op == "-" then r = a - b elseif op == "*" then r = a*b elseif op == "/" then r = a/b else error("invalid operation") end"How to use functions in Lua" is introduced here, thank you for reading. If you want to know more about industry-related knowledge, you can pay attention to the website. Xiaobian will output more high-quality practical articles for everyone!

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.