oop - When should I declare variables in a PHP class? -


i'm new oop paradigm, there's simple explanation question...

do need declare public object-wide variables in class? example:

<?php  class testclass {     var $declaredvar;      function __construct()     {         $this->declaredvar = "i declared variable.";         $this->undeclaredvar = "i wasn't declared, still work.";     }      function display()     {         echo $this->declaredvar . "<br />";         echo $this->undeclaredvar;         echo "<br /><br />";      } }  $test = new testclass; $test->display();  $test->declaredvar = "the declared variable changed."; $test->undeclaredvar = "the undeclared variable changed.";  $test->display();  ?>

in code, though $declaredvar declared variable, $undeclaredvar accessible , useable--it seems act if had declared public.

if undeclared class variables accessible that, what's point of declaring them front?

that variable isn't uninitialized, it's undeclared.

declaring variables in class definition point of style readability. plus can set accessibility (private or public).

anyway, declaring variables explicitly has nothing oop, it's programming-language-specific. in java can't because variables must declared explicitly.


Comments

Post a Comment

Popular posts from this blog

javascript - Jquery show_hide, what to add in order to make the page scroll to the bottom of the hidden field once button is clicked -

i have button on website when clicked, reveals map. button can seen when page first loads up, when clicked, section holding map slides open , goes out of screen since page loads @ top (normal). want page scroll down bottom of div select when button pushed, if map out of screen. if page scrolled down, , clicks show map button, don't want page jump bottom of map. i tried figure out myself, no luck. seasoned jquery coders able give me guidance? many thanks! map = mapdiv.gmap3("get"); infobox = new infobox({ pixeloffset: new google.maps.size(-220, -310), closeboxurl: '', enableeventpropagation: true }); mapdiv.delegate('.infobox .close','click',function () { infobox.close(); }); jquery(".slidingdiv").hide(); jquery(".show_hide").show(); jquery('.show_hide').click(function(){ lastcenter=map.getcenter(); jquery(".slidingdiv&quo
Read more

javascript - Highcharts multi-color line -

Image
i looking create highchart multi-colored line. if goes down under value, become red, , when comes on value, become green . here picture example: or maybe highcharts have other charts models differentiate high or low level color? you can achieve coloring using lineargradient coloring: color: { lineargradient: { x1: 0, x2: 0, y1: 0, y2: 1 }, stops: [ [0, 'red'], [0.25, 'yellow'], [0.50, 'green'], [0.75, 'yellow'], [1, 'red'] ] } here 0 in stops relates minimum value of series , 1 maximum value, , in between percentages between values. if find percentages according values prior creating chart use correct stops values make relate specific values in data (at least approximately). see this jsfiddle example .
Read more

javascript - Enter key does not work in search box -

tried search guys sorry. input in search box doesnt work (or search) when hit enter when user clicks search button. doing wrong? here code. thanks. <script type="text/javascript"> $(document).ready(function() { $("#submit").click(function() { var url = "http://asla.org/awardssearch.html"; url += "?s=" + $('#googlecse').val(); window.location = url; }); $('#googlecse').keydown(function(event) { if (event.keycode == '13') { $("#submit").click(); } else { //do nothing :) } }); }); </script> <form class="navbar-form navbar-right" role="search"> <div class="search"> <input id="googlecse" type="text" onblur="if(this.value=='')this.value=this.defaultvalue;" onfocus="if(this.value==this.defaultvalue)t
Read more