Three Outputs of an Empty Array:
print_r(): Array ( )
var_dump(): array(0) { }
var_export(): array ( )

Three Outputs of a Filled Array:
print_r(): Array ( [0] => Monday [1] => Tuesday [2] => Wednesday [3] => Thursday [4] => Friday [5] => Saturday [6] => Sunday )
var_dump(): array(7) { [0]=> string(6) "Monday" [1]=> string(7) "Tuesday" [2]=> string(9) "Wednesday" [3]=> string(8) "Thursday" [4]=> string(6) "Friday" [5]=> string(8) "Saturday" [6]=> string(6) "Sunday" }
var_export(): array ( 0 => 'Monday', 1 => 'Tuesday', 2 => 'Wednesday', 3 => 'Thursday', 4 => 'Friday', 5 => 'Saturday', 6 => 'Sunday', )

The array has 7 entries.

Foreach loop over Days:
Monday
Tuesday
Wednesday
Thursday
Friday
Saturday
Sunday

Foreach loop with Key=>Value Pairs:
0 => Monday 1 => Tuesday 2 => Wednesday 3 => Thursday 4 => Friday 5 => Saturday 6 => Sunday

For loop with Index Access:
Monday
Tuesday
Wednesday
Thursday
Friday
Saturday
Sunday