Echo or print_r when php develops an api and outputs json data. how can this problem be solved?

Echo or print_r when php develops the api and outputs json data. Suppose $ selectRows is an array and then outputs (that is, when an external call is used) whether it is echo, return, or print_r. Why can't I find it externally? I am echourlencode (json_encode ($ selectRows), and echo or print_r when I output json data through the php development api?
Assume that $ selectRows is an array before output (that is, when an external call is used) echo, return, print_r, and so on. Why can't I find it externally? echo urlencode (json_encode ($ selectRows), $ gc = file_get_contents (http: // domain name/class name/method name/incoming value) but $ gc can be directly output during output, but print_r (urldecode (json_decode ($ selectRows ))) when I print the array, nothing is left.

------ Solution --------------------
$ SelectRows is the output of your array like this: echo urlencode (json_encode ($ selectRows ));
Echo json_decode (urldecode ($ gc) after getting $ gc with file_get_contents ));
That's right.