php use function, print php, php echo and php use function

Print :

This function displays output on browse and returns value true if output is printed successfully, otherwise it returns false.

Example

<?php

                        $a= print”codelack”;

                        Print”<br>”;

                        Print $a;  // returns either true or false.

          ?>

<?php

$a= print”codelack”;

Print”<br>”;

Print $a; // returns either true or false.

Output: codelack<br/>1

Echo:

It is same as print but it does not return any value so that its performance is faster than print function.
We can also print multiple statements with an echo function.

Example

<?php

 Echo "codelack", "com","tutorial" ;

?>

<?php

Echo "codelack", "com","tutorial" ;

Output: codelackcomtutorial.

var-dump:

using this function we can display the value of variable along with data types.

  <?php
      $k=100;

     $y="codelack";

      Var_dump($k);

      Var_dump($y);
  ?>

<?php

$k=100;

$y="codelack";

Var_dump($k);

Var_dump($y);

Output: int (100) string 8 codelack

Printf:-

Using this function we can print variables with the help of format specifiers.

<?php

$k=100;

$h="codelack”;

Printf(“%d”,$k);

Printf(“%s”,$h);

?>

<?php

$k=100;

$h="codelack”;

Printf(“%d”,$k);

Printf(“%s”,$h);

Output : 100 codelack

Print_r:

Using this function, we can display all elements of array and properties of object.

<?php

$arr=array(10,20,40,50);

Print_r($arr);

?>

<?php

$arr=array(10,20,40,50);

Print_r($arr);

Output: array

[0]=10

[1]=20

[3]=40

[4]=50

NOTE : On viewing the source code , the array is shown systematically on the screen.