php repeat loop Infinite

Question

Im trying to achieve something simple like repeating colors for each element.

Here is my function:

function colors() {
   $colorArray = array('#f44336', '#9c27b0', '#e91e63');
   return $colorArray[array_rand($colorArray)];
}



<ul>
    <li style="color:<?php echo colors(); ?>"><span>Word</span></li>
    <li style="color:<?php echo colors(); ?>"><span>Word</span></li>
    <li style="color:<?php echo colors(); ?>"><span>Word</span></li>
    <li style="color:<?php echo colors(); ?>"><span>Word</span></li>
    <li style="color:<?php echo colors(); ?>"><span>Word</span></li>
    <li style="color:<?php echo colors(); ?>"><span>Word</span></li>
    <li style="color:<?php echo colors(); ?>"><span>Word</span></li>
    <li style="color:<?php echo colors(); ?>"><span>Word</span></li>
    <li style="color:<?php echo colors(); ?>"><span>Word</span></li>
    <li style="color:<?php echo colors(); ?>"><span>Word</span></li>
    <li style="color:<?php echo colors(); ?>"><span>Word</span></li>
    <li style="color:<?php echo colors(); ?>"><span>Word</span></li>
    <li style="color:<?php echo colors(); ?>"><span>Word</span></li>
    <li style="color:<?php echo colors(); ?>"><span>Word</span></li>
    <li style="color:<?php echo colors(); ?>"><span>Word</span></li>
    <li style="color:<?php echo colors(); ?>"><span>Word</span></li>
    <li style="color:<?php echo colors(); ?>"><span>Word</span></li>
    <li style="color:<?php echo colors(); ?>"><span>Word</span></li>
    <li style="color:<?php echo colors(); ?>"><span>Word</span></li>
    <li style="color:<?php echo colors(); ?>"><span>Word</span></li>
    <li style="color:<?php echo colors(); ?>"><span>Word</span></li>
    <li style="color:<?php echo colors(); ?>"><span>Word</span></li>
    <li style="color:<?php echo colors(); ?>"><span>Word</span></li>
    <li style="color:<?php echo colors(); ?>"><span>Word</span></li>
</ul>

this works fine, but I would like not to have random colors, instead keep repeating first 3 colors from array. I could have as many as 500 items, so the loop must be able to run infinite.

idk what you want to do? more than 3 colours? infinity amount of list items? — Sebastian Tkaczyk
– Sebastian Tkaczyk, Commented Sep 11, 2017 at 15:54
@Sebastian Tkaczyk I want 3 colors but infinite number of items. — Alko
– Alko, Commented Sep 11, 2017 at 16:06

Mike S · Accepted Answer · 2017-09-11 16:25:27Z

1

If you want to alternate the three colors then you need to keep a record of the last color used. Here is a simple modification to your function requiring the use of a static variable:

function colors() {
    static $colorCounter = -1;
    $colorArray = array('#f44336', '#9c27b0', '#e91e63');
    $colorCounter++;
    return $colorArray[$colorCounter % count($colorArray)];
}

Here is the example output (three colors repeated infinitely): https://eval.in/859522

edited Sep 11, 2017 at 16:25

answered Sep 11, 2017 at 16:13

Mike S

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5 Comments

musicnothing Over a year ago

As long as you're setting the counter as a global variable, why not make the colors global as well to avoid the reassignment on each call?

Mike S Over a year ago

I was going for the least amount of changes to the OPs code but that's a good point.

musicnothing Over a year ago

That makes sense.

Niet the Dark Absol Over a year ago

Consider using a static variable instead - function colors() {static $counter = 0; ... } - avoids polluting global scope.

Mike S Over a year ago

Great suggestion @NiettheDarkAbsol - updated the example.

Niet the Dark Absol · Accepted Answer · 2017-09-11 16:21:17Z

1

Use CSS.

li:nth-child(3n+1) {color: #f44336;}
li:nth-child(3n+2) {color: #9c27b0;}
li:nth-child(3n+3) {color: #e91e63;}

Much cleaner :p

answered Sep 11, 2017 at 16:21

Niet the Dark Absol

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1 Comment

Mike S Over a year ago

A great CSS alternative if the OP can live without IE8 support.

Dedering · Accepted Answer · 2017-09-11 16:13:47Z

0

Create a global variable to store the index each time it is used. Increment that variable during each iteration -- if greater than the count of the array return to zero.

// Create a global variable
$current_color = -1;  

function colors() {
    // Access global var
    global $current_color;  
    // Array of colors
    $colorArray = array('#f44336', '#9c27b0', '#e91e63');  
    // Increment global var 
    $current_color++;  
    // Return to zero if var is greater than the count of your array
    $current_color = ( $current_color < count( $colorArray ) ) ? $current_color : 0;  
    // Return color
    return $colorArray[$current_color]; 
}

answered Sep 11, 2017 at 16:13

Dedering

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1 Comment

Dedering Over a year ago

@neuromatter If your global doesn't start at -1 you will start with the second color.

iainn · Accepted Answer · 2017-09-11 16:30:55Z

0

Any excuse to have fun with InfiniteIterator

<?php
class Colors
{
    private $infinite;

    public function __construct(array $colors)
    {
        $this->infinite = new InfiniteIterator(new ArrayIterator($colors));
        $this->infinite->rewind();
    }

    public function get()
    {
        $return = $this->infinite->current();
        $this->infinite->next();

        return $return;
    }
}

$colors = new Colors(['#111', '#222', '#333']);

Just call echo $colors->get() whenever you want a color. See https://eval.in/859523

answered Sep 11, 2017 at 16:30

iainn

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