Concatenating a Parameter Variable

+ VS. +=

Concatenating a Parameter Variable with +=

runPlusEqualsLocal() :  

Concatenating a Parameter Variable with +

runPlusLocal() :  

Concatenating a Local Variable with +

runPlusLocal() :  

Tip: concatenate with + instead of +=

Tip: If you're using a parameter variable, and you use +=, don't reassign the parameter variable. This will allow the browser to optimize your code for you. IE and Mozilla will do this.