PHP Learning Notes: Function Declaration_PHP Tutorial

Copy code The code is as follows:

/* Function definition:
* 1. A function is a Named
* 2. Independent code segment
* 3. Function performs a specific task
* 4. And can return a value to the program that calls it
*
* Advantages of functions :
* 1. Improve program reusability
* 2. Improve program maintainability
* 3. Can improve development efficiency
* 4. Improve software reliability
* 5 .Control the complexity of the program
*
* Function declaration
* function function name(){
*
* }
*
* function function name (parameter 1 , parameter 2, parameter...)
* {
* function body
* }
*
* function function name()
* {
* function body;
* return value;
* }
* function function name (parameter list...)
* {
* function body;
* return value
* }
*
* Note:
* 1. The function must be called to be executed. It can be called before or after the declaration
* 2. The function name is the same as the variable, aaa bbb ccc aaaBbbCcc (The first word is lowercase, and the first letter of each subsequent word is capitalized)
* 3. Functions cannot have the same name when declaring them
* 4. You can change the behavior of the function by passing parameters to the function
* Formal parameters : When declaring a function, the declared parameters are variables. Multiple parameters are separated by
* Actual parameters: When calling the function, the formal parameter value (data, which can also be a variable) is passed to
* 5. If If there is no return value, it is called a process
* 6. Return data by using the return statement
* 7. The function execution ends when it reaches the return statement. Do not write code after this statement. You can also use return to end the execution of the function
*
* The role of the function name:
* 1. Call the function and start executing the function
* 2. You can pass data to the function
* 3. The function name is the returned value
*
*
*/
//A function that outputs a table
function table($tablename,$width,$row,$col)
{
echo '';
echo '

'.$tablename.'

< ;/caption>';
for($i=0;$i{
//Change color every other row
if($i%2==0)
$bg="#cccccc";
else
$bg="yellow";
echo ' ';//output row
for($j=0;$j{
echo ''.($i*$row+$j).'{
echo '';
echo '';
for($i=0;$i{
//Change colors on alternate lines
if($i%2==0)
$bg="#cccccc";
else
$bg="yellow";
echo '';//Output line
for($j=0;$j{
echo '';
}
echo '';

}
echo '

'.($i*$row+$j).'

';

}/td>';
}
echo ' ';

}
echo '';

}
table("Output table",600,10,10);
table("Output table 2",300,6,6) ;

//Another output method
function table2($tablename,$width,$row,$col)
{
$str='';
$str.= '';// Output rows
for($j=0;$j{
$str.='';
}
$str.='';

}
$str.='

'.($i*$row+$j).'

';

return $str;
}

echo table2("Direct output table",400,15,15);
?>

http://www.bkjia.com/PHPjc/323569.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/323569.htmlTechArticleCopy code The code is as follows: ?php /* Function definition: * 1. A function is a named * 2. Independent code segment* 3. The function performs a specific task* 4. And can return a value to the program that calls it...