1. data Type: scalar type: INTEGER (int), float (float), string (string), boolean (boolean) conforming type: array, object) other types: resource, NULL2. $ a123; echo11 $ a; $ a indicates echo11 $ a11; $ a indicates no. php $ a11 indicates a by default.
1. data Type: scalar type: INTEGER (int), float (float), string (string), boolean (boolean) conforming type: array, object) other types: resource, NULL 2. $ a = 123; echo 11 $ a; // $ a can call echo 11 $ a11; // $ a cannot be used. By default, php $ a11 is
1. Data Type:
Scalar type: INTEGER (int), float, string, boolean)
Conformity type: array, object)
Other types: resource, NULL
2. $ a = "123 ";
Echo "11 $ a"; // $
Echo "11 $ a11"; // $ a cannot be used. php $ a11 is a variable by default. The solution is as follows:
Echo "11 {$ a} 11"; // php only parses the variables in braces
3. There cannot be anything before the end of the delimiters. It must be written in the top line.
$ A = <
123
Xxx; // write in the top line
Echo $;
4. boolean type with a value of false:
FALSE, 0, 0.0, empty string, string 0, NULL, empty array