Notices tagged with javascript, page 18

#javascript convert array to map
new Map([...["a", "b", "c"].entries()]);
Array.prototype.entries http://xahlee.info/js/js_Array.prototype.entries.html

learn #JavaScript es2015 the Map Object in 5 minutes http://xahlee.info/js/javascript_map.html

#JavaScript learn ECMAScript 2015 Features in depth in 1 hour
Example based. To the point. No ninja zen cool bullshit.
http://xahlee.info/js/js_ECMAScript_2015_features.html

#javascript a summary of all regex methods, how they differ
http://xahlee.info/js/js_regex.html

today's #javascript tips.

String.prototype.search
http://xahlee.info/js/js_String.prototype.search.html

String.prototype.match
http://xahlee.info/js/js_String.prototype.match.html

RegExp.prototype.exec
http://xahlee.info/js/js_RegExp.prototype.exec.html

say you want to learn #JavaScript. but, the js accounts there, all tweets bleeding incomprehensible ephemeral things, mostly marketing + click bait. There is basically no account that you can actually learn something. How did we get to this point?

those spamming click bait accounts, i suppose, they work in statical fashion. i.e. they tweet a ton, and vast majority usually perhaps on twitter just 1 hour a day. So, as long as some random thumb up them, overal, spammy works out as optimal strategy

this is how to create a range function in #JavaScript
const xah_range = ((n) => [...Array(n).keys()] ) ;
It'll take 1 month to understand how that js code works.
involves spread operator, iterable, interface.
The semantics of js is more complex than perl python ruby lisp java.

#JavaScript Array.prototype.keys
http://xahlee.info/js/js_Array.prototype.keys.html
and
Array.prototype.values
http://xahlee.info/js/js_Array.prototype.values.html
are idiotic. They return 0,2,3... or the array values.

#JavaScript surprised to find out that Array.prototype.values() is not supported by Google Chrome, Firefox. Also, it's a entirely useless method.

if you haven't mastered #emacs abbrev yet, do today.

6 months ago, i've been happily using

u → you
r → are
ur → your
ull → you'll
hv → have
haven't → haven't
n → and
dnt → don't

, 1 thousand others for elisp, #javascript, etc.

here's how to setup
http://ergoemacs.org/emacs/emacs_abbrev_mode.html

worked 10 hours on my tutorial
JavaScript in Depth
http://xahlee.info/js/js.html

new or updated pages include:

#JavaScript Object.prototype.__proto__
http://xahlee.info/js/js_Object.prototype.__proto__.html

JS: Get/Set Prototype
http://xahlee.info/js/js_find_objects_prototype.html

JS: “in” Operator
http://xahlee.info/js/js_in_operator.html

#JavaScript Spread Operator
http://xahlee.info/js/javascript_spread_operator.html

JS: Iterator
http://xahlee.info/js/javascript_iterator.html

JS: Array.prototype.entries
http://xahlee.info/js/js_Array.prototype.entries.html

Massive Upgrade JavaScript in Depth to ES2015

here's 5 pages for end of the year day.

JS: Replace All Children, createDocumentFragment
http://xahlee.info/js/js_dom_createDocumentFragment.html

JS: String.prototype
http://xahlee.info/js/js_string_methods.html

JS: String Object
http://xahlee.info/js/js_string_properties.html

JS: String.prototype.constructor
http://xahlee.info/js/js_String.prototype.constructor.html

#javascript RegExp Syntax
http://xahlee.info/js/js_regex_syntax.html

web tech is changing and adding features very fast.
Animation on the web, current states of the art
http://xahlee.info/js/svg_animation.html
#javascript

massive updates to my #JavaScript tutorial. Here's 5 pages for today.

JS: RegExp Tutorial
http://xahlee.info/js/js_regex_tutorial.html

JS: RegExp.prototype.exec
http://xahlee.info/js/js_RegExp.prototype.exec.html

JS: Convert String to Number
http://xahlee.info/js/js_convert_between_string_and_number.html

JS: Function Declaration vs Function Expression
http://xahlee.info/js/javascript_function_declaration_vs_expression.html

JS: Function Parameters
http://xahlee.info/js/javascript_function_arguments.html

#javascript simplest way to add method to prototype
http://xahlee.info/js/js_prototype.html

#JavaScript quiz. x.y.z Associativity, Right or Left?
http://xahlee.info/js/js_x.y.z_associativity_right_or_left.html

understand #JavaScript function's “arguments” object in 3 minutes http://xahlee.info/js/js_function_arguments_object.html

the best explanation of #JavaScript Iterator you'll ever see http://xahlee.info/js/javascript_iterator.html

#JavaScript 3 ways to Find Object's Prototype
http://xahlee.info/js/js_find_objects_prototype.html

understand #JavaScript Global Variable, Implied Global, Global Property, in 5 minutes.
http://xahlee.info/js/javascript_global_var.html