the difference of echo&print function

There is a difference between the two, but speed-wise it should be irrelevant which one you use.  print() behaves like a function in that you can do:  $ret = print "Hello World";And $ret will be 1That means that print can be used as part of a more complex expression where echo cannot.  print is also part of the precedence table which it needs to be if it is to be used within a complex expression. It is just about at the bottom of the precendence list though.  Only "," AND, OR and XOR are lower.echo is marginally faster since it doesn't set a return value if you really want to get down to the nitty gritty.If the grammar is: echo expression [, expression[, expression] ... ]Then echo ( expression, expression ) is not valid.  ( expression ) reduces to just an expression so this would be valid: echo ("howdy"),("partner");but you would simply write this as: echo "howdy","partner"; if you wanted to use two expression.  Putting the brackets in there serves no purpose since there is no operator precendence issue with a single expression like that.