604 !!expr (two ! operators followed by an expression) returns the primitive true or false depending on the truthiness of the expression. It makes sense when used on non-boolean expressions. Some …

Nov 5, 2008 · 3611 Can I convert a string representing a boolean value (e.g., 'true', 'false') into an intrinsic type in JavaScript? I have a hidden form in HTML that is updated based on a user's …

Is there a really easy way to toggle a boolean value in javascript? So far, the best I've got outside of writing a custom function is the ternary: bool = bool ? false : true;

Mar 3, 2015 · The easiest way to check for true and false is: (typeof value === "boolean"), but if value is an instance of the Boolean class, then it will return "object". So to handle that, we must add another …

Due to the two boolean evaluations submitInput() is only called if the given input is a string that contains non-whitespace characters. In JavaScript && returns its first argument if it is falsy or its second …

Mar 7, 2011 · I typically expect that when someone says they want to "parse a string into a boolean" they mean that they want to map the string "false" to the boolean value false. However in javascript, …

How to convert a string to Boolean ? I tried using the constructor Boolean("false"), but it's always true.

Mar 26, 2013 · If I declare a JavaScript boolean variable like this: var IsLoggedIn; And then initialize it with either true or 1, is that safe? Or will initializing it with 1 make the variable a number?

May 13, 2009 · What is the use of: var flag = new Boolean(false); compared to: var flag = false; When would you actually use new Boolean?

JavaScript traces its ancestry back to C, and C does not have a logical XOR operator. Mainly because it's not useful. Bitwise XOR is extremely useful, but in all my years of programming I have never …