Php learning notes function declaration

Copy codeThe Code is as follows:
<? Php
/* Function Definition:
* 1. The function is named
* 2. Independent code segments
* 3. The function executes a specific task.
* 4. You can return a value to the program that calls it.
*
* Advantages of functions:
* 1. Improve program reusability
* 2. Improve the maintainability of the program
* 3. Improved development efficiency
* 4. Improve Software Reliability
* 5. Complexity of the control program
*
* Function declaration
* Function name (){
*
*}
*
* Function name (parameter 1, parameter 2, parameter ...)
*{
* Function body
*}
*
* Function name ()
*{
* Function body;
* Return value;
*}
* Function name (parameter list ...)
*{
* Function body;
* Return Value
*}
*
* Note:
* 1. functions must be called before execution. They can be called before declaration or after declaration.
* 2. The function name is the same as the variable name. aaa bbb ccc aaaBbbCcc (the first word is lowercase, And the last letter is uppercase)
* 3. The function name cannot be repeated during declaration.
* 4. You can change the function behavior by passing parameters to the function.
* Form parameters: When declaring a function, the declared parameters are variables. Multiple parameters are used and separated.
* Real parameter: The parameter value (data or variable) is passed when a function is called)
* 5. A process is called if no return value exists.
* 6. return data using the return Statement
* 7. When the function is executed, the return statement ends. You can use return to end the function execution instead of writing code after this statement.
*
* Function Name:
* 1. Call the function and start executing the function.
* 2. data can be transferred to the function.
* 3. The function name is the returned value.
*
*
*/
// Function of an output table
Function table ($ tablename, $ width, $ row, $ col)
{
Echo '<table border = "1" width = "'. $ width. '" align = "center"> ';
Echo '<caption> For ($ I = 0; $ I <$ row; $ I ++)
{
// Change the color of the line
If ($ I % 2 = 0)
$ Bg = "# cccccc ";
Else
$ Bg = "yellow ";
Echo '<tr bgColor = "'. $ bg. '">'; // output line
For ($ j = 0; $ j <$ col; $ j ++)
{
Echo '<td>'. ($ I * $ row + $ j). '<function table ($ tablename, $ width, $ row, $ col)
{
Echo '<table border = "1" width = "'. $ width. '" align = "center"> ';
Echo '<caption> For ($ I = 0; $ I <$ row; $ I ++)
{
// Change the color of the line
If ($ I % 2 = 0)
$ Bg = "# cccccc ";
Else
$ Bg = "yellow ";
Echo '<tr bgColor = "'. $ bg. '">'; // output line
For ($ j = 0; $ j <$ col; $ j ++)
{
Echo '<td>'. ($ I * $ row + $ j). '</td> ';
}
Echo '</tr> ';

}
Echo '</table> ';

}/Td> ';
}
Echo '</tr> ';

}
Echo '</table> ';

}
Table ("output table", 10 );
Table ("output table 2", 6 );

// Another Output Method
Function table2 ($ tablename, $ width, $ row, $ col)
{
$ Str = '<table border = "1" width = "'. $ width. '" align = "center"> ';
$ Str. = '<caption> For ($ I = 0; $ I <$ row; $ I ++)
{
// Change the color of the line
If ($ I % 2 = 0)
$ Bg = "# cccccc ";
Else
$ Bg = "yellow ";
$ Str. = '<tr bgColor = "'. $ bg. '">'; // output row
For ($ j = 0; $ j <$ col; $ j ++)
{
$ Str. = '<td>'. ($ I * $ row + $ j). '</td> ';
}
$ Str. = '</tr> ';

}
$ Str. = '</table> ';

Return $ str;
}

Echo table2 ("direct output table", 15, 15 );
?>