What is the difference between single-quoted and double-quoted strings in PHP?

Question

I'm not an expert in PHP programming, but I'm a little confused why I see some code in PHP with string placed in single quotes and sometimes in double quotes. I just know in .NET, or the C language, if it is in single quote, that means it is a character, not a string.

Answer 1

With PHP when I first used it in a major application, it didn't matter which way. But when I started college you have to learn syntax and that's a major play in all coding languages. It's a little bit cleaner to use double quotes for a string and then single quotes. This would be a good example:

<?php

$servername = "127.0.0.1";

$username = "username";

$password = "password";

$dbname = "database";

// Create connection

$conn = new mysqli($servername, $username, $password, $dbname);

// Check connection

if ($conn->connect_error) {

die("Connection failed: " . $conn->connect_error);

}

$sql = "SELECT * FROM management ";

$result = $conn->query($sql);

// Profile Query: Pulling From Main Database

if ($result->num_rows > 0) {

// output data of each row

while ($row = $result->fetch_assoc()) {

$Name = $row['Name'];

$Job = $row['Main_Job'];

$image_src = $row['Image'];

echo "<div class='Cards'>";

echo "<img src= '$image_src'>";

echo "<div class='Cards-Container'>";

echo "<h4>$Name</h4>";

echo "<p>$Job</p>";

echo "</div>";

echo "</div>";

}

}

?>