Syntax

YJLO Script has similar syntax as JavaScript or Swift with support for higher order functional programming and object-oriented programming.
Semicolon separator at the end of each statement is optional (since ver 0.3.0).

Comments

YJLO Script supports both line comments // and block comments /* ... */, likes other C-like languages.

Identifiers

YJLO Script is a case-sensitive language. Identifiers start with a letter and may contain letters, digits, and underscores.
The following examples are all valid identifiers:

a
count
sum2
Hello_World
isValid

Declare a variable with an initial value:

var myVar = "Hello"

To declare a variable with a specified initial value, you can use the short variable declaration operator :=.

myVar := "Hello"

All variable's default value is null if the initial value is not given.

Declare multiple variables in one line:

var a = 0, b = "abc", c
/*
EQUIVALENT TO:
a := 0
b := "abc"
c := null
*/

Assigning one value to multiple variables is allowed.

var a, b, c
a = b = c = 4

However, assigning one value to multiple variables in var statement is not allowed.

var a = b = 4 // ERROR

Instead, use := to declare multiple variables and initialize them with the same value.

a := b := 4
print(a, b) // OUTPUT 4 4

Scope

Unlike JavaScript (ES5 and older versions), YJLO Script is block-scoped. Every pair of braces {} defines a new scope. Local variables declared in a scope are visible to its own scope as well as all sub-scopes, but invisible to its parent-scopes.

a := 1
func bar(){
	a := 2
	b := 3
	print( a )		// output 2
	if (true) {
		print( b )	// output 3
		c := 4
		print( c )	// output 4
	}
	print( c )		// Error: Cannot find variable: c
}
bar()
print( a )		// output 1
print( b )		// Error: Cannot find variable: b