Syntax:
if (condn - 1)
{
//code to be executed - block - I
}
else if (condn - 2)
{
//code to be executed - block - 2 
{
else if (condn - 3)
{
//code to be executed - block - 3
}
else
{
//default code to executed
}
Example:
\(\$\)x = 10, \(\$\)y = 20,\(\$\)ch = 3, \(\$\)z = 0;
if(\(\$\)ch == 1)
{
\(\$\)z=\(\$\)x+\(\$\)y;
}
else if (\(\$\)ch == 2)
{
\(\$\)z=\(\$\)x-\(\$\)y;
}
elseif (\(\$\)ch == 3)
)
\(\$\)z=\(\$\)x\(\$\)y;
}
else
{echo "Invalid choice please try again";
}
echo answer is \(\$\)z";
?>

(i) Each else is associated with another if statement.
(ii) Evaluation of condition starts from top to down.
(iii) If condition becomes true then the associated block with if statement is executed and rest of conditions are skipped.
(iv) If the condition becomes false then it will check for next condition in a sequential manner.
(v) It repeats until all conditions are checked or a true condition is found.
(vi) If dl condition available in else ... if ladder evaluates to false then default else block will be executed. Uses: Else . .. if ladder provides multi way decision making when anyone alternative is to be select among the available option.

< ?php
＄x = "August";
if (＄x == "January'') {
echo "Happy Republic Day";
}
elseif (＄x == "August'') {
echo "Happy Independence Day!!!";
}
else{
echo "Nothing to show";
}
? >

< ?php
＄x = -12;
if (＄x > 0)
{
echo "The number is positive";
}
else{
echo "The number is negative";
}
? >

< ?php
＄date=date("m-d'');
if (＄date== > >01-10 > >)
{
echo "Wishing you a very Happy Birthday";
}
? >

< ?php·
＄d=date("D'');
if(＄d=="Fri'')
{
echo"Have a nice weekend!";
}
Else
{
echo"Have a nice day!";
}
? >