PHP Learning Note-----The difference between double quotation marks and single quotes

1 single quotation marks

1) Single quotation mark does not parse variable, if need in single quotation mark input variable, will output variable name directly

2) do not parse escape character, only parse \ ' and \ \ (i.e. single quotation mark itself and backslash)

3) to enter single quotes in single quotes, you need to add an escape slash (see 2)

2 double Quotes

1) Double quotation marks can parse variables, in most cases to be enclosed in curly braces, it is recommended to always add, such as $name= ' Leevian '; $str = "I am {$name}";

2) Double quote parsing escape character

3) Double quotes with an escape character in the output double quotation mark

Note: Single and double quotes can be interpolated ~ No escape characters are required.

PHP Learning Note-----The difference between double quotation marks and single quotes