String Literal Concatenation: + VS +=

Using +=

runPlusEqualsLiteral() :  

Using +

runPlusLiteral() :  

String literal concatenation:

"foo" + "bar"

String variable concatenation:

var f ="foo";
f = f + "bar"

Tip: concatenate with + instead of +=

Tip: String literals are extremely fast in Mozilla

Tip: Concatenating String literals in Mozilla takes almost 0 time!