With this function you can check whether a global scope variable exists or not. You supply the global variable name to check for as a string (see example code below) and the function will return true if a global variable with the given name exists or false otherwise.NOTE: This function is primarily for use with Compatibility Scripts for imported projects and the converted code for Drag and Drop actions.
Argument Description name The name of the global variable to check for (as a string)
if !variable_global_exists("enemy_num")) global.enemy_num = instance_number(obj_Enemey_Parent);
The above code will check to see if the global variable called "enemy_num" exists and if it does not it is created and set a value.