Summary introduction of eight data types in PHP

This article introduces to you a summary of the eight data types in PHP. It has certain reference value. Friends in need can refer to it. I hope it will be helpful to you.

PHP supports a total of eight data types, including 4 scalar types, namely boolean (Boolean type), integer (integer), float/double (floating point type) and string (string type); two types Composite types, namely array and object; two special types, resource and bull.

1. Scalar data type

1. boolean )

Boolean is one of the more commonly used data types in PHP. It saves a True or false value. Among them, True and FALSE are the internal keywords of PHP. To set a Boolean variable, just assign true or false to the variable. In PHP, not only boolean values ​​are false, but non-boolean values ​​are also considered false in some special cases. For example, 0, empty string and just declare array without assignment.

2. String type (String)

strings are continuous string sequences, which are composed of numbers, letters and symbols. Each character in the string takes up only one byte. There are three ways to define strings, single quotes, double quotes, and delimiters (<<<)

Variables contained in backticks are output as ordinary characters, such as $i=' I am the most handsome', echo '$i' will output $i, and double quotes will parse the variable and output "I am the most handsome"!

3. Integer type (integer)

Integer data type can only contain integers. In a 32-bit operating system, the valid value range is -2147483648~ 2147483647.

4. Float type (float)

Floating point data type can be used to store integers, integers, or decimals.

                                                                                                                                                                                              Arrays can include a lot of data, such as scalar data, arrays, objects, resources, and other syntax structures supported in PHP. Each data in the array is called an element, and the element includes two parts: index (key name) and value. The index of an element can consist of a number or a string, and the value of an element can be of multiple data types.

                                                                                                                                                                                                   2. Object

I still don’t understand what an object is

Special resource type

Resource null value(null)

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