4.9 Initialization

• In the absence of explicit initialization, external and static variables are initialized to zero; automatic and register variables have undefined/garbage initial values
• For external and static variable, initializer must be a constant expression; initialization is done once, before the program begins execution
• For automatic and register variable, initializer is not restricted to be a constant expression, it can be previously defined values or function calls; initialization is done each time the function or block is entered
• An array may be initialized by following its declaration with a list of initializers enclosed in braces and separated by commas. ie:

• When the size of array is omitted, compiler will compute the length by counting the initializers
• For character arrays initialization, a string may be used instead of the braces and commas notation: