PHP Basic Learning Record 1

Data type

• In PHP, 8 primitive types are supported, including four scalar types, two composite types, and two special types (resource, empty type). PHP is a loosely typed language, and PHP automatically converts variables to automatic data types without having to declare the variable's data type to PHP.
• Boolean type: When we use the "echo" command to Output a Boolean type, if "true" then the output is "1", "false" will not output anything.
• String type:

The string type can be defined in three ways: single-quote, double-quote, and Heredoc-structured.

When the string contains quotation marks, the first scenario: double quotation marks are embedded in single quotation marks, and the second scenario is to embed single quotation marks in double quotation marks; The third scenario: Use the escape character "\".

When a variable is enclosed in double quotes, the variable is concatenated with the contents of the double quotation mark, and the variable is exported as a string when the variable is included in the single quotation mark.

Heredoc form:

　　　

PHP Basic Learning Record 1