javascript Programming Glossary: falsey

What is the consequence of this bit of javascript?

http://stackoverflow.com/questions/1031718/what-is-the-consequence-of-this-bit-of-javascript

run if the left hand side of the statement evaluates to a falsey value. So if jQuery.ui already exists on the page then the function..

falsey values in javascript

http://stackoverflow.com/questions/3982663/falsey-values-in-javascript

values in javascript I had an interesting interview question.. question today that stumped me a little. I was asked about falsey values. So undefined NaN null 0 an empty string all evaluate.. share improve this question One dangerous issue of falsey values you have to be aware of is when checking the presence..

(![]+[])[+[]]… Explain why this works

http://stackoverflow.com/questions/4170978/explain-why-this-works

false it was truthy false it was truthy 0 true it was falsey NaN true it was falsey After it we have the second operand of.. false it was truthy 0 true it was falsey NaN true it was falsey After it we have the second operand of the addition an empty..

Conflicting boolean values of an empty JavaScript array

http://stackoverflow.com/questions/4226101/conflicting-boolean-values-of-an-empty-javascript-array

false is truthy true negation The only values that are falsey are null undefined 0 NaN an empty string false Anything else..

Javascript || or operator with a undefinded variable

http://stackoverflow.com/questions/4576867/javascript-or-operator-with-a-undefinded-variable

undefined . It is also true that x will be 10 if v has any falsey value. The falsey values in javascript are 0 null undefined.. also true that x will be 10 if v has any falsey value. The falsey values in javascript are 0 null undefined NaN empty string false.. var v 0 var x v 10 alert x alerts 10 Assign v any of the falsey values that I indicated above and you'll get the same result...

Can someone explain this 'double negative' trick?

http://stackoverflow.com/questions/4686583/can-someone-explain-this-double-negative-trick

true otherwise returns true. So if getContext gives you a falsey value the will make it return the boolean value false . Otherwise.. boolean value false . Otherwise it will return true . The falsey values are false NaN undefined null empty string 0 share improve..

Convert NaN to 0 in javascript

http://stackoverflow.com/questions/7540397/convert-nan-to-0-in-javascript

You can do this a a 0 ...which will convert a from any falsey value to 0 . The falsey values are false null undefined 0 empty.. 0 ...which will convert a from any falsey value to 0 . The falsey values are false null undefined 0 empty string NaN Not a Number..