A practical guide to the development of LUA games Learning Note 2

Learn lua in depth

First, the function

functions are the main tools for dividing game scripts.

The function starts with the function keyword followed by the name of the argument and then the list of arguments, ending with the end keyword

650) this.width=650; "title=" 1.jpg "src=" Http://s3.51cto.com/wyfs02/M01/54/80/wKioL1SFK8KCthhjAAA3UkNssQk519.jpg " alt= "Wkiol1sfk8kcthhjaaa3uknssqk519.jpg"/>

Example of a single parameter

function SetName (myString)

Print ("")

Print ("Your name is:", myString)

Print ("")

End

"MyString" is passed to the function and used in the function, and the arguments in the function are local variables, which are recycled after the call is finished .

Lua can define a variable-length parameter list, using the (... Instead of the parameter list, LUA creates a local table with the name ARG, saves all invocation arguments, and the number of arguments (obtained by ARG.N)

function Howmany (...)

...

End

return value

function uses the return keyword followed by a numeric value (usually a variable name) to return the result

function Timestwo (my)

my = my * 2

return my

End

Function can also return multiple results

function Threedice ()

D1 = Math.random (1,6)--Take random numbers

D2 = Math.random (1,6)

D3 = Math.random (1,6)

Mytotal = D1+d2+d3

Return d1,d2,d3,mytotal

End

You can also call another function using return

Standard library

assert (myvalue) ()

The Assert function can run a compiled block of code like a function (chunk)

Dofile (filename)

Dofile loads and immediately executes a LUA script file, typically used to load a defined file for invocation, or to load a data file (such as an archive)

Example: Dofile ("Scripts/function.lua")

mathematical Operators , LUA provides a function-level mathematical operator that can invoke the C standard library.

Math.Abs	Take absolute value		Math.max	The maximum value in a collection
Math.acos	Inverse cosine function		Math.min	The minimum value in a collection
Math.asin	Inverse chord function		Math.mod	Take the mold
Math.atan	Inverse tangent function		Math.pow	Two x x, y
Math.atan2			Math.rad	Angle to radians
Math.ceil	Take a minimum integer value that is not less than the function parameter		Math.sin	Zheng Xuan
Math.Cos	Yu Xuan		Math.sqrt	Calculate square root
Math.deg	Radian to Angle		Math.tan	Tangent
Math.exp	Calculates the exponential power of E. parameter is exponential		Math.frexp	Exponential calculation, two parameters, first parameter is base, second parameter is exponent

Math.floor	Rounding down		Math.ldexp	Exponential calculation (x*2^y), two parameters, first parameter x is, second parameter is exponential
Math.log	Calculates the pair value of an e-based parameter X		Math.random	Random generation of pseudo-random numbers between 0~1
Math.log10	With Math.log		Math.randomseed	Set random number Seed

Common functions

Math.floor ()

The floor function is used to take down the whole (the concept of no floating-point or integer in Lua), which is simply to take out the fractional part

such as: a = 5.125

b = 5.72

Print (Math.floor (a))

Print (Math.floor (b))

The output is all

5

5

If you want to achieve rounding , then you can add 0.5 to a, b

Math.random ()

Math.random randomly generates pseudo-random numbers between 0~1, and Lua can pass in the maximum and minimum values, randomly generating numbers in this range.

such as: Mfdie = Math.random (1,6)

Math.min (), Math.max ()

Math.min () determines the maximum and minimum values in a collection

Update to here today first ...

A practical guide to the development of LUA games Learning Note 2