PHP mathematical operations and data processing example analysis_php skills

The examples in this article describe PHP mathematical operations and data processing methods. Share it with everyone for your reference, the details are as follows:

1. Numeric data type

In PHP, the use of numeric or numerical data and mathematical functions is very simple. Basically, there are two data types to deal with: floating point numbers and integers. The internal representation of floating point and integer values ​​are the C data types double and int respectively. Similar to C, these data types in PHP follow the same set of rules.

PHP is a loosely typed scripting language, and variables can change data types according to calculation needs. This allows the engine to perform type conversions dynamically. So, if a calculation contains a numeric value and a string, the string is converted to a numeric value before the calculation is completed, and the numeric value is converted to a string before being concatenated with the string.

<&#63;php
$a = '5';
$b = 7 + $a;
echo "7 + $a = $b";
&#63;>

PHP provides a large number of functions to check the data type of variables. There are 3 functions that check whether a variable contains a numeric value, or more specifically, whether a variable is a float or an integer.
The function is_numeric() can check whether the value passed as a parameter is a numeric value.

The functions is_int() and is_float() are used to check specific data types. If an integer or floating point number is passed in, these functions will return true, otherwise they will return false, even if a string with a legal numerical representation is passed in, false will be returned.

You can also force the engine to change data types. This is called type casting, which can be achieved by adding (int), (integer), (float), (double) or (real) in front of the variable or value, or by using the function intval() or floatval() .

2. Random number

Random numbers are a science in themselves. There have been many different implementations of random number generators. PHP implements two of them: rand() and mt_rand(). The rand() function is a simple wrapper around a random function defined in libc, one of the basic libraries provided by the compiler used to build PHP. mt_rand() is a good alternative implementation that provides many well-designed features, and mt_rand() is even faster than the version in libc.

Both functions provide some functions to get the value of MAX_RAND. rand() is getrandmax(), mt_rand() is mt_getrandmax();

3. Format data

In addition to warnings, errors and other information, most of PHP's output is generated using functions such as echo, print() and printf(). These functions convert the argument into a string and send it to the client application.
The number_format() function converts integers and floating-point values ​​into a readable string representation.

<&#63;php 
$i = 123456;
$si = number_format($i,2,".",",");
echo $si;
&#63;>

4. Math functions

abs() absolute value
floor() rounding by rounding
ceil() round to the nearest integer
round() rounds
min() finds the minimum value or the minimum value in an array
max() finds the maximum value in the maximum array

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I hope this article will be helpful to everyone in PHP programming.