Trimming whitespace
PHP provides three functions that trim leading or trailing whitespace characters-null, tab, vertical-tab, newline, carriage-return, and space characters-from strings:
string ltrim(string subject) string rtrim(string subject) string trim(string subject)
The three functions return a copy of the subject string: trim( ) removes both leading and trailing whitespace characters, ltrim( ) removes leading whitespace characters, and rtrim( ) removes trailing whitespace characters. The following example shows the effect of each:
$var = trim(" Tiger Land\n"); // "Tiger Land"
$var = ltrim(" Tiger Land\n"); // "Tiger Land\n"
$var = rtrim(" Tiger Land\n"); // " Tiger Land"
Rendering newline characters with <br>
Whitespace characters generally don't have any significance in HTML, but it's often useful to preserve newlines when a page is rendered. The nl2br( ) function generates a string by inserting the HTML break element <br /> before all occurrences of the newline character in the source argument:
XHTML-compliant br tag
From PHP Version 4.0.5 onwards,nl2br( )inserts the XHTML-compliant<br />markup that includes the shorthand way of closing an empty element. Earlier versions inserted<br>, which isn't valid XML.
string nl2br(string source)
The following example shows how nl2br( ) works:
// A short poem $verse = "Isn't it funny\n"; $verse .= "That a bear likes honey.\n"; $verse .= "I wonder why he does?\n"; $verse .= "Buzz, buzz, buzz.\n"; // The four lines are rendered as one echo $verse; // Renders the poem on four lines in HTML as intended echo nl2br($verse);