I know javascript "(x)" can memorize pattern and match ,but I have a question about it. here is my code:
var re = /(\w*)(abc)\1\2/;
var str = '123dabc123dabc'
console.log(re.exec(str))
var re = /(\w*)(abc)\1\3/;
var str = '123dabc123dabc'
console.log(re.exec(str)) // this must be null,because "\3" is not the right pattern,but what·s the "\3" ·s match rules in here
I want to know which str \3
can match ?...