Wa-lang's Manual

The content on this page is written in Chinese, and then traslated into English by machine. More accurate traslations are welcome at: https://github.com/wa-lang/man/tree/master/en

Ending's law: "Any application that can be compiled to WebAssembly, will be compiled to WebAssembly eventually."

3.1. Local variable declaration

Chapter 2 introduces global variable and constant declarations. Also commonly used is local variable (variables defined within a function) declaration. Its general syntax is:

VarName: Type = initial Value

What is different from all variables and constants is that the declaration of local variables does not start with a keyword; when declaring a local variable, if the = initial value part is omitted, the variable will be initialized with a value of 0, such as:

    aI32: i32 = 42
    aString: string = "你好"
    aF32: f32  // 0.0

Another commonly used syntax for declaring local variables uses the short-declaration :=. The syntax is as follows:

VarName := expression

When using this writing method, the type of the variable will be consistent with the type of the expression on the right side of the short-declaration, and the value of the expression will be assigned to the initial value of the local variable, such as:

    a := 13          // int
    f := 3.14        // f64
    s := genString() // string
...
func genString() => string { return "Hello" }

Wa-lang is a statically typed language. The type of a legal expressions can be inferred at compile time, so the type of a expression is determined. The := syntax is similar to C++'s auto type.