In AngularJS, why should I use a $ at the beginning of a scope object name? -


no js experience. learning angularjs

so i've read https://docs.angularjs.org/guide/scope, , i've looked @ stackoverflow.com answers on $ used in javascript. understand $ has specific use in libraries, jquery, , in newer versions of javascript seen standard character variable names. question is...

why common in angularjs see scope object $ in front of though $ isn't necessary?

an example of angularjs scope object without using $

scope object without $

app.controller('maincontroller', ['$scope', function(withoutdollarsign){     withoutdollarsign.title = 'string here'; }]);

or scope object $

app.controller('maincontroller', ['$scope', function($withdollarsign){     $withdollarsign.title = 'string here'; }]);

the angular api documentation states:

angular prefixes $ , $$: prevent accidental name collisions code, angular prefixes names of public objects $ , names of private objects $$. please not use $ or $$ prefix in code.

in code snippet, showing 1 method dealing dependency injection. in method, array of arguments passed, , array matched, in order, parameters passed in function. customary, not mandatory, use same name array value value being passed function. using different names can create confusion in code, looking @ code later, might not understand @ first glance withoutdollarsign $scope.

in practice, $ or $$ used developer identify objects created framework, vs. objects created in own code. there no special significance in javascript language usage, convention used angular contributors.

as stated here, it's recommended not use $ or $$ in own code when interacting angular framework.


Comments

Post a Comment

Popular posts from this blog

c# - Validate object ID from GET to POST -

i have method allows user access comment have made on site. have post method lets them update comment. my normal solution send entire comment model through, let them update it, update on database when post back. involve sending commentid through in hiddenfor , can manipulated. how can verify commentid sent in get method same i'm getting in post , not able alter comment wish? how can verify commentid sent in method same i'm getting in post? basically have validate following things in post - user logged-in user. authenticated users post comments. commentid in post , should valid commentid , should present in database. userid associated logged-in user should same userid associated comment . comment should contain userid column, can check @ time of update. to make sure update happens comment has been sent in get - hold commentid in session , in post action compare commentid value in session .
Read more

node.js - Custom Model Validator SailsJS -

when using custom model validator checks record within model. return within spread doesn't seem end control flow. //post.js model /** * custom validator **/ types: { isuservalid: function(user_id) { var promise = require('bluebird'); promise.all([ user.findone({id: user_id}) ]) .spread(function(user) { console.log(user); if (user === null || user === undefined) { console.log('failed'); return false; }else{ console.log('passed'); return true; } }); } }, my response standard validation failed response. { "error": "e_validation", "status": 400, "summary": "1 attribute invalid", "model": "post", "invalidattributes": { "owner": [ { "rule": "isuservalid", ...
Read more

php - Find a regex to take part of Email -

i have following emails need extract part from: bestellnummer xxx: 1 von xxx, 1er pack ------------- anfang der nachricht ------------- foo bar baz foo bar baz // <<<<< need text here ------------- ende der nachricht ------------- ------------- anfang der nachricht ------------- foo bar baz foo bar baz ------------- ende der nachricht ------------- there 0 unlimited occurences of ------------- anfang der nachricht ------------- ------------- ende der nachricht ------------- and i'm able extract first part regex: $re = "/------------- .*? -------------.?(.*?).?------------- .*? -------------/s"; but, i'm quite new on learning regex, i'm pretty sure there must better regex extract part (foo bar baz foo bar baz) of text between ------------- anfang der nachricht ------------- ------------- ende der nachricht ------------- as can in different languages, i'm using .? to match between hyphens. i...
Read more