String Functions in PHP

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. PHP uses the '.' dot operator to join strings
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. $first_name = 'Charlie';
. $last_name  = 'Brown';
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. $full_name = $first_name . ' ' . $last_name;
. $full_name = "$first_name $last_name";
. $full_name = "{$first_name} {$last_name}";
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. LEFT MID RIGHT Equivalent
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. Depending on your background, you may have come across these string functions:
. LEFT, MID, RIGHT. Below I will show you how you can achieve RIGHT in PHP using
. substr.
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. Syntax for RIGHT is RIGHT(string, length) - eg if string = "abcdefgh" and you
. issue RIGHT(string, 4), you get "efgh", the last four characters. You can
. achieve a similar result in PHP by using substr(string, -4).
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. $rest = substr("abcdef", 1);    // returns "bcdef"
. $rest = substr("abcdef", 1, 3); // returns "bcd"
. $rest = substr("abcdef", 0, 4); // returns "abcd"
. $rest = substr("abcdef", 0, 8); // returns "abcdef"
.
. // Accessing via curly braces is another option
. $string = 'abcdef';
. echo $string{0};                // returns a
. echo $string{3};                // returns d
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. $rest = substr("abcdef", -1);    // returns "f"
. $rest = substr("abcdef", -2);    // returns "ef"
. $rest = substr("abcdef", -3, 1); // returns "d"
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. preg_grep
. preg_last_error
. preg_match_all
. preg_match
. preg_quote
. preg_replace_callback
. preg_replace
. preg_split
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. preg_replace -- Perform a regular expression search and replace
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. echo preg_replace($pattern, $replacement, $string);
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. $searchstr = preg_replace('#[^a-zA-Z0-9_-]#', ' ', $searchstr);
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