Php Basics (2)-Special

Php Basics (2) -- Special 1. "+" is not a string connector, "12a" + "a" = 12, and the string connector is ". "2. echogettype (-3% 2);-1 reserved symbol, integerechogettype (-3/2);-1.5double3. more logical operators: xor logic exception or php basic knowledge (2) -- Special

1. "+" is not a string connector, "12a" + "a" = 12, and the string connector is ". "2. echo gettype (-3% 2);-1 reserved symbol, integer echo gettype (-3/2);-1.5 double3, more logical operators: xor logic exclusive or (logical AND, logical or, logical or, non-logical) 4. call the parent class constructor: parent :__ construct () 5. variable name variable: $ change_name = "huhu"; $ huhu = "change_name variable changed"; echo $ change_name; // output: huhu $ change_name = "restored"; echo"
"; Echo $ huhu; // output: restored resolution: $ huhu and $ change_name point to the same memory. 6. variable function go () {echo" Gone ";} $ func = "go"; func (); the go () function is called. it can be used to implement callback functions and function tables, but variable functions cannot be used in language structures, such as echo (), print (), unset (), isset (), empty (), include (), require (), and similar statements echo $ change_name; // output: the change_name variable is changed 7. break $ num; the number of repeated loops exceeded, such as the while set for foreach8 and switch ($ var) $ var: any type