What does comma mean in PHP? Don't you use a dot "." to connect?

Question

Answer 1

This is not about concatenating strings. echo can output multiple variables at the same time. If multiple variables are output, using commas is much more efficient than using dot syntax to assemble, eliminating the need for variable parsing in the string. It seems , you still don’t understand the basic syntax of PHP very well. It is recommended to make up the basics