PHP String, Escape Sequences and Concatenation

PHP String, Escape Sequences and Concatenation

In this chapter, you will learn about PHP String, differences between single and double quotes, PHP escape sequences, and PHP concatenation.

Navigation –

  • PHP String Data Type
  • Escape Sequences
  • Concatenation

PHP String Data Type

A string is a sequence of characters that are inside single or double quotes.

String Example –

<?php
echo "a string - inside the Double quotes";
echo "<br>";//line breaker
echo 'a string - inside the single quotes';
?>
Browser Output
a string – inside the Double quotes
a string – inside the single quotes

You can assign strings in variables –

<?php
$x = "Hello John";
$y = 'Hi Jane';

echo $x;
echo "<br>";
echo $y;
?>
Browser Output
Hello John
Hi Jane

Difference between PHP Single quotes and Double quotes

PHP single quotes can’t parse variables data but double quotes can, for that PHP Variable Interpolation only works with double quotes.

<?php
$first_name = "John";
$last_name = "Doe";
$full_name = "$first_name $last_name";

echo "$fullname";
echo "<br>";// line breaker
echo '$full_name';
?>
Browser Output
John Doe
$full_name

In single quotes, only two escape sequences work and they are –

  • \' single quote
  • \\ backslash

But, all Escape Sequences works with double quotes.

Example is below –


PHP Escape Sequences

Escape sequences are used to escape a character, during the string parsing, and It is also used to give special meaning to represent line breaks, tabs, etc.

\ Backslash is used to escape.

In the above, we have already discussed that you can only escape single quotes and backslash inside the single quotes. Here’s an example –

<?php
//using a backslash to escaping a single quote
echo 'Hi I\'m John Doe';

echo '<br>';

//using a backslash to escaping a backslash
echo '\\ this is a backslash';

echo '<br>';

echo 'Hi I\\\'m John Doe';
?>
Browser Output
Hi I’m John Doe
\ this is a backslash
Hi I\’m John Doe

And we have also discussed that all escape sequences work with double quotes. Here’s an example –

<?php
echo "\"Double Quotes\"";
echo "<pre>\$dollar sign \nThis is new line \n\tA new line with tab Space</pre>";
?>
Browser Output
“Double Quotes”
$dollar sign
This is new line 
	A new line with tab Space

Checkout – the list of Escaped characters


PHP Concatenation

You can Join two string together using PHP Concatenation or string operators.

In PHP, there are two string operators –

  • First is the concatenation operator ('.')
  • Second is the concatenating assignment operator ('.=')

Concatenation operator Example –

This operator returns the concatenation of its right and left arguments.

<?php
$x = "John";
$y = "Doe";
$z = $x.$y;

echo "Hello "."world";

echo "<br>";//line breaker
echo $x." Doe";

echo "<br>";//line breaker
echo $x.$y;

echo "<br>";//line breaker
// adding space
echo $x." ".$y;

echo "<br>";//line breaker
echo $z;
?>
Browser Output
Hello world
John Doe
JohnDoe
John Doe
JohnDoe

Concatenating assignment operator Example –

This assignment operator appends the argument on the right side to the argument on the left side.

<?php
$x = "John";
$y = " Doe";

$x .= $y;

echo $x;
?>
Browser Output
John Doe

Next is – PHP HereDoc, NowDoc, and HereDoc VS NowDoc

Previous is – PHP echo, print, echo VS print, Variable Interpolation

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