PHP and MySQL

6.2    Language Constructs

Language constructs are not functions. However, they are very similar to functions. You can tell the difference in two ways:

• Language constructs can include parameters without round brackets. Thus,

  echo "Test";  

  is just as possible as

  echo("Test");.  

• Language constructs cannot be stored in variables, and the variable cannot be accessed. The following therefore fails (see Figure 6.21):

  <?php  $functionname = "echo";  $functionname("test"); ?>  

  

  Figure 6.21     The Call to the "echo()" Function Fails because It Is a Language Construct

And even beyond these two points, which always apply, language constructs have some ...