Type conversion in PHP
Getting the type of a variable To get the type of a variable, use the gettype() ...
Checking for Variable Existence in PHP
If the variable is declared, but it was not initially assigned any value (in oth...
Constants in PHP
Constants, like variables, store a certain value, only unlike variables, the val...
Variable scope In PHP
When using variables and functions, consider the scope of variables. The scope d...
PHP Arrays
Earlier we looked at how variables can store a single value, such as a single nu...