what is the use of usort () and lambda function in php.? explain with examples
usort is used in php4,php5,php6.
It is used for sorting array which is defined by user.
syntax:: usort(array,function_name)
for example::
<?php
function sort($i,$j)
{
if($i==$j)
return 0;
else
return ($i>$j?-1:1;
}
$i=array(1,2,3,4,5,6,7,8,9)
usort($i,"sort");
?>
Lambda is an anonymous function .It is used with array_map(), array_filter(), array_reduce functions of php.
For example::
<?php
$greeting=function()
{
return "hello";
}
echo $greeting();
?>