I think this question is wrong... Either world should be in single quote and used as variable later or hello should b in single tag...

Answer 1

Where is the question?

Answer 2

i don't know what the question

Answer 3

Yes, since both variables were in double quotes the question does not make sense. In that case the variable $a would not use the variable $hello, it actually assigns the string "Hello" to the variable so $a shouldn't print "World" it should actually print "Hello"

Answer 4

Php variable variable question..