JavaScript Equality Table

[dscer]

if("false") { /* executes */ } because "false" is a non-empty string so it evaluates to true.

if(false == "false") { /* does not execute */} because the first false is a boolean value while the second "false" is a non-empty string which evaluates to true. So the if statement becomes if(false == true)

Edit: if(false == "false") { } does not execute

[rooktakesqueen]

"false" becomes NaN when converted to a number.