Syntax:string preg_quote (string $str, string $delimiter = NULL)
Parameters : - $str:This parameter contains the input string.
- $delimiter:This is an optional parameter. The most common delimiter is ’ / ’ because it is not a special regex character that is usually handled by the preg_quote() function. Mostly used in conjunction with the preg_replace() function .
Returns: returns a delimiter containing a string.The following program illustrates the preg_quote() function.
Program 1:
/ / Create the string to be escaped
$str
=
" Welcome to GfG! (+ The course fee. $400) / "
;
echo
" Before Processing - "
.
$str
. PHP_EOL;
// Use preg_quote() in the above line
$processedStr
= preg_quote (
$str
);
// Show output
echo
"After Processing -"
.
$processedStr
;
?>
Exit:Before Processing - Welcome to GfG! (+ The course fee. $400) / After Processing - Welcome to GfG! (+ The course fee. $400) /
Note that every special character is preceded by a backslash, but not for a forward slash. For this we can use a separator, see the Program below:Program 2
// Create a string to be escaped
$str
=
"Welcome to GfG! (+ The course fee . $400) / "
;
echo
" Before Processing - "
.
$str
. PHP_EOL;
// Use preg_quote() in the above line
$processedString
= preg_quote (
$str
,
’/’
);
// Show output
echo
"After Processing -"
.
$processedString
;
?>
Exit:Before Processing - Welcome to GfG! (+ The course fee. $400) / After Processing - Welcome to GfG! (+ The course fee. $400) /
The program below demonstrates the combination of the functions preg_quote()and preg_replace() .Program 3:
// PHP program highlights the word inside * * and
// use font style for italics in [] using
// both functions preg_quote() and preg_replace()
$str
=
" The * article * was written by [GFG] "
;
// Words to format
$word1
=
"* article *"
;
$word2
=
"[GFG] "
;
// The first line is only applied in bold to word 1,
// preg_quote() escapes * *
$processedStr1
= preg_replace (
"/"
. preg_quote (
$word1
,
’/’
)
.
"/"
,
" "
.
$word1
.
"
"
,
$str
);
echo
" BOLD ONLY - "
.
$processedStr1
. PHP_EOL;
// The second line applies only italics
// word 2, preg_quote() escapes []
$processedStr2
= preg_replace (
" / "
. preg_quote (
$word2
,
’/’
)
.
"/"
,
""
.
$word2
.
"< / em >"
,
$str
);
echo
" ITALIC ONLY - "
.
$processedStr2
. PHP_EOL;
// Combine both text formatting and display
$bothReplacementsCombined
= preg_replace (
"/"
.
preg_quote (
$word2
,
’/’
).
"/"
,
""
.
$word2
.
"< / em >"
,
$processedStr1
);
echo
" BOTH COMBINED - "
.
$bothReplacementsCombined
;
?>
Exit:BOLD ONLY - The * article *was written by [GFG] ITALIC ONLY - The * article * was written by [GFG] BOTH COMBINED - The * article * was written by [GFG]
Note:To notice the text formatting tags being applied, you must run PHP on your local server and navigate to a browser.