String's character acces speed

• labelstring
• labelperformance
• labelcharat
• labelbracket-notation

Formatter Reuse vs Creation

getElementById vs querrySelector

Compare the performance of the getElementById and querrySelector...

• labelquerryselector
• labelgetelementbyid
• labelperformance

Wrapping value in Promise vs checking if it's promise like

typeof + instanceof vs instanceof with hasInstance performance for type checking

typeof arg == 'undefined' vs arg == undefined