mysqli - Unable to insert into Mysql db from PHP -

the following code generating integer value in variable $insertstatement, insert statement failing have tried long time couldn't figure out reason issue appreciated :)

<?php $con=mysqli_connect("localhost","root","","loadtest");  if (mysqli_connect_errno()) {   echo "failed connect mysql: " . mysqli_connect_error(); }  if( $_get["value"] != null ||  $_get["value"]!="" ) {     $rand=uniqid();     $insertstatement="";     date("m-d-y");     for($i=0;$i<$_get["value"];$i++){         $insertstatement +="insert test values('"+$date+"','"+$rand+"','column1','column2','column3','column4','column5','column6','column7','column8','column9','column10');";     }     echo $insertstatement;     mysqli_query($con,$insertstatement)or die("cannot insert");     mysqli_close($con);     echo "<p style=\"color:green\">inserted</p>"; }  else{     echo "couldn't insert"; } ?> 

change this:

$insertstatement +="insert test values('"+$date+"','"+$rand+"','column1','column2','column3','column4','column5','column6','column7','column8','column9','column10');"; 

to this:

$insertstatement .="insert test values('" . $date . "','" . $rand . "','column1','column2','column3','column4','column5','column6','column7','column8','column9','column10');"; 

to concatenate strings in php use ..

echo "a" + "b"; // outputs 0 echo "a" . "b"; // outputs "ab" 

read: http://php.net/manual/en/language.operators.string.php