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MEL and Expressions

Blocks

A block is a group of expressions that can stand in for a single expression. Blocks are surrounded by curly braces:

{ 
	print("Hello there."); 
	print("Glad to meet you."); 
	print("So long!"); 
} 

For example, the if statement has this form:

if (condition) 
	exp1 

exp1 can be a single expression:

if ($x > 5) 
	print("It's more than 5!"); 

...or a block of expressions:

if ($x > 5) { 
	print("It's more than 5!"); 
	$x = 0; 
	$y++; 
} 

Blocks will become important when you start to use conditional and looping statements.

Very important note

In MEL, unlike most languages, all statements inside a block (surrounded by curly braces) must end in semicolons, even if it is the only statement in the block.

if ($s > 10) {print("Glonk!")}  // Syntax error. 
if ($s > 10) {print("Glunk!");} // Notice the semicolon. 

Variable scope in blocks

Blocks can also be useful to limit the scope of a variable, since any local variable declared in a block is only visible inside that block:

int $test = 10; 
{ 
	int $test = 15; 
	print($test+"\n"); 
} 
print($tt+"\n"); 
// Result: 
15 
10