Question

I cannot find out the regex to get param value from the part of query string:

I need to send parameter name to a method and get parameter value as result for string like
"p=1&qp=10".
I came up with the following:

function getParamValue(name) {

  var regex_str = "[&]" + name + "=([^&]*)";

  var regex = new RegExp(regex_str);

  var results = regex.exec(my_query_string);
  // check if result found and return results[1]

}

My regex_str now doesn’t work if name = 'p'. if I change regex_str to

var regex_str = name + "=([^&]*)";

it can return value of param 'qp' for param name = 'p'

Can you help me with regex to search the beginning of param name from right after '&' OR from the beginning of a string?

Answer 1

This might work, depending on if you have separated the parameter part.

var regex_str = "(?:^|\&)" + name + "=([^&]*)";
or
var regex_str = "(?:\&|\?)" + name + "=([^&]*)";