different from programming variables •Booleans different from natural language (e.g. inclusive-or vs. exclusive-or) •Arrays start at 0, people usually count from 1 •Variable names and keywords are case sensitive •= is often confused with == •123 is confused with “123” •Some variables are passed by reference, other by value •Having to put “break” in every switch statement causes errors •Unnecessary syntax: a++ and a+=1 http://www.cs.cmu.edu/~NatProg/OldMarch162007/langeval.html https://docs.google.com/document/d/1X_V5b0E4qKeSViZcTvpurLb67NfR5GzTUvnh2zZiaWg/edit?usp=sharing Usability issues for novice programmers: Monday, December 2, 13
from other languages • JS usability itself is not well researched :-( http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.133.4831&rep=rep1&type=pdf Monday, December 2, 13
','. I thought you were going to type an identifier but you typed ‘,’! I think you meant to type a value or variable name before that comma? Original Conversational Specific + Actionable Monday, December 2, 13
type an identifier but you typed )! → I think you either have an extra comma or a missing argument? var x = 5; x+x=1; Bad assignment! → The left side of an assignment must be a single variable name, not an expression. 140= 141 + 142; Bad assignment! text;() I thought you were going to type an assignment or function call but you typed an expression instead! More Newbie Syntax Errros Monday, December 2, 13
itself Make a dev tool plugin http://developer.chrome.com/extensions/devtools.html http://blog.mozilla.org/addons/2009/01/28/how-to-develop-a-firefox-extension/ Write a blog post Monday, December 2, 13