DEV Community: Talha Shinwari

Variable by Reference & Variable by Value in PHP

Talha Shinwari — Tue, 13 Aug 2024 19:10:10 +0000

In PHP, variables can be passed in two primary ways: by value and by reference. Understanding the difference between these two concepts is crucial for effective PHP programming.

1. Variable by Value

When you pass a variable by value, a copy of the original value is made and assigned to the new variable. This means that changes made to the new variable do not affect the original variable.
Example:

$a = 5;
$b = $a; // $b is assigned the value of $a
$b = 10;

echo $a; // Outputs: 5
echo $b; // Outputs: 10

In this example, $b is a copy of $a. Changing $b does not affect $a.

2. Variable by Reference

When a variable is assigned by reference, both variables point to the same memory location. Changes to one variable will affect the other.

$a = 5;
$b = &$a; // $b is a reference to $a
$b = 10;

echo $a; // Outputs: 10
echo $b; // Outputs: 10

Here, $b is a reference to $a. Changing $b also changes $a because they both refer to the same value.

Passing by value creates a new copy, which uses more memory, while passing by reference uses the same memory location.
n pass-by-value, changes to the new variable do not affect the original. In pass-by-reference, changes to either variable affect the other.

When to Use Each?

Pass by Value: Use when you want to keep the original variable unchanged.
Pass by Reference: Use when you need to modify the original variable within a function or another context.

Understanding the difference between passing variables by value and by reference in PHP helps in writing efficient and predictable code. Use pass-by-reference when you need to alter the original variable, and pass-by-value when you want to preserve the original data.

Mini Profile Card in HTML CSS

Talha Shinwari — Fri, 28 Jan 2022 11:32:32 +0000

Random background LogIn page in HTML CSS

Talha Shinwari — Tue, 25 Jan 2022 16:07:01 +0000

I Design this LogIn page with random background images through Unsplash API, By every refresh, it will be different. Highly recommended for beginners to master their basic skills.

Academic Calender in HTML-Only

Talha Shinwari — Wed, 19 Jan 2022 16:19:17 +0000

Time Table with only HTML

Talha Shinwari — Wed, 19 Jan 2022 06:55:16 +0000

This is an HTML-only Time table design, you can practice the table attribute very well. Get the idea from the attached source code and design your own.

Flexbox Practice HTML, CSS

Talha Shinwari — Fri, 10 Dec 2021 16:27:41 +0000

HTML

<body>

        <div class="container">
        <div class="flex">ONE</div>
        <div class="flex">TWO</div>
        <div class="flex">THREE</div>
        <div class="flex">FOUR</div>
        <div class="flex">FIVE</div>
        <div class="flex">SIX</div>
        <div class="flex">SEVEN</div>
        <div class="flex">EIGHT</div>
    </div>

</body>

CSS

.container{
    display: flex;
    flex-wrap: wrap;
    background-color: darkmagenta;
    justify-content: flex-start;

}

.flex{
    display: flex;
    width: 200px;
    height: 200px;
    margin: 10px;
    border: 2px solid black;
    border-radius: 5px;
    box-sizing: border-box;
    background-color: yellow;
    justify-content: center; 
    align-items: center; 
   font-size: large;
   font-weight: 1000;
}

Social Network

Talha Shinwari — Thu, 16 Sep 2021 12:15:47 +0000

Landing page

Talha Shinwari — Thu, 16 Sep 2021 12:14:38 +0000