Php single quotes

$ B110; $ typegettype ($ B); echo333. & amp; quot; $ type \ n & amp; quot; echo333. $ type \; output 333string333 $ type \ 1. when entering something in double quotation marks, you can determine whether the variable is included. if the variable is included, output 2 together. the values in single quotes are different. if you do not judge whether a variable exists, all the values are output as strings...

$ B = '000000'; $ type = gettype ($ B); echo '000000'. "$ type \ n"; echo '000000'. '$ type \\';

Output

Php code

333 string

333 $ type \

1. when entering something in double quotation marks, you can determine whether the variable is included. if the variable is included, the output is made together.

2. the single quotes are different. if you do not judge whether there are any variables, they are all output as strings.

3. the time for parsing single quotes is faster than that of double quotes.

4. single quotation marks support \ escape characters, and double quotation marks support multiple escape characters