Anthony Gargiulo agargiulo

true and false vs. "truthy" and "falsey" (or "falsy") in Ruby, Python, and JavaScript

Many programming languages, including Ruby, have native boolean (true and false) data types. In Ruby they're called true and false. In Python, for example, they're written as True and False. But oftentimes we want to use a non-boolean value (integers, strings, arrays, etc.) in a boolean context (if statement, &&, ||, etc.).

This outlines how this works in Ruby, with some basic examples from Python and JavaScript, too. The idea is much more general than any of these specific languages, though. It's really a question of how the people designing a programming language wants booleans and conditionals to work.

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	/*<?php
	///public class PhpJava { public static void main(String[] args) { System.out.printf("/%s",
	//\u000A\u002F\u002A
	class PhpJava {
	static function main() {
	echo(//\u000A\u002A\u002F
	"Hello World!");
	}}
	//\u000A\u002F\u002A
	PhpJava::main();

	# Import xchat module
	import xchat

	# Required module information
	__module_name__ = "loose cannon"
	__module_version__ = "1.0"
	__module_description__ = "Annoy the ops, namely agargiulo"

	# Define the callback method for our hook
	def loose_cannon_cb(word, word_eol, userdata):

	#include <stdio.h>
	#include <setjmp.h>
	#include <stddef.h>
	#include <string.h>

	#define NORETURN __attribute__((noreturn))

	typedef void (AllocCont)( void );

	void NORETURN longjmp_on_return( AllocCont f, jmp_buf env, void *mem ) {

Anthony Gargiulo agargiulo

true and false vs. "truthy" and "falsey" (or "falsy") in Ruby, Python, and JavaScript

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