Find a PHP custom function to regulate the price two decimal places .

Look it up and read Zheng Shen's "BC High Cluster Chain Accuracy Respect Function Library".

Note: To use the bc library, you need to add the --enable-bcmath option when compiling a php program.

The round() function in PHP can be used to implement the round() function against floating-point numbers.

Make rounding.

round(x,prec)

Parameter description. x Optional.

Numbers that are scheduled to be rounded.

Prec optional. Specify the number of decimal places.

Returns the result of rounding x to the specified precision prec (the number of decimal places). prec can also be negative or zero (the default).

Note: PHP doesn't handle things like that correctly by default"12,"strings.

For example: echo round(,2);

Output:

I'll give you an example.

n=round(, 2);

This is rounded to 2 decimal places.

round(,2);

Rounded to two decimal places.

If three is a decimal place, it is a decimal place, and the number after the decimal point is less than 4 and is not carried, and if it is greater than or equal to 5, it is carryed. You can search for what significant figures are.

You can't try that? Try changing 10 to 100, 1000, and see.

echo sprintf("%",;

Formatting the output directly will do the trick.

$num ="";

printf("is number is:%.2f",$num);Output:2f is $num and preprocessed to two decimal places.

round($num, 2);

An integer is a number without a decimal point.

if(!strstr('.',$num))

Actually, you can use PHP's built-in functions.

Erh, why do you want to customize a function?

PHP has a built-in function is int($num) This can determine whether a number is an integer or not!!

If you must write one yourself, I can help you, the principle is to use the regular rule to get it done, do you need it?

This should be based on the actual situation, if you need to return value, you can add return, if you don't need to, you can not add, the difference between the two is that the actual needs are different, and the other is that if you add return, the response time of the program will be slightly longer, however, this time will generally not have any effect. For example:

You're going to output a string:

function type_str()

In this case, you can, but if you want to judge whether the output is successful, you have to write this:

function type_str()else return false;

You can tell if the output is successful by the return value of the program. There are also some custom functions that also need to be returned after processing, so you have to use return. For example:

function add($a , b)

After the function runs, all the variables defined inside the function will be destroyed, so be sure to return $sum so that the results you process are not wasted.

Here's a little trick to you: echo and print are different, echo is not a function, and there is no return value, so you can't write it.

if(echo "123"), but print is a function, it has a return value, true if it succeeds, false if it fails, you can write: if(print("123"));Something like that. So print is a little slower than echo, usually just use echo.

It is not necessary to return a value to the function in the first place, sometimes (such as output) the function does not need to return a value, if you want to return a value, you use return, and if your argument uses address passing, you don't need to add reruen He automatically returns the change to the argument.

PHP functions are divided into system intrinsic functions and custom functions.

Custom Functions Use function to customize a function:

Format: function func name($val) The name of the function is the same as that of a custom variable, you can only use ,a z, a z, a zThe variables in a custom function are local, and when the global global variable is not valid outside the function, the variable can be used outside the function (not recommended) In order to place the chaos of the global variable, you can use unset($var) to delete a variable instance:

function _pr()pr();

The output: This is a custom function.

of the assignment ---