Some Important PHP Functions

Some String Functions in Php

1.      String Length in Php:

<?php
echo strlen("Hello world!");
?>

2.      String Position

<?php
echo strpos("Hello world!","world");
?>

3.      String Constant

<?php
define("GREETING", "Welcome to W3Schools.com!");
echo GREETING; // not Case-sensitive.
echo greeting;

?>

Note: Every time we echo GREETING it will print Welcome to W3Schools.com!

4.      Some Tricky arithmetic operations are

<?php 
$x=10; 
echo $x; // outputs 10

$y=20; 
$y += 100;
echo $y; // outputs 120

$z=50;
$z -= 25;
echo $z; // outputs 25

$i=5;
$i *= 6;
echo $i; // outputs 30

$j=10;
$j /= 5;
echo $j; // outputs 2

$k=15;
$k %= 4;
echo $k; // outputs 3
?>

5.      String Operations

<?php
$a = "Hello";
$b = $a . " world!";
echo $b; // outputs Hello world! 

$x="Hello";
$x .= " world!";
echo $x; // outputs Hello world! 
?>

6.      PHP foreach loop

<?php 
$colors = array("red","green","blue","yellow"); 
foreach ($colors as $value)
  {
  echo "$value <br>";
  }
?>

7.      User Defined Function in PHP

<?php
function writeMsg()
{
echo "Hello world!";
}
writeMsg(); // call the function
?>

8.  Function argument

<?php
function familyName($fname)
{
echo "$fname Refsnes.<br>";
}

familyName("Jani");
familyName("Hege");
familyName("Stale");
familyName("Kai Jim");
familyName("Borge");
?>