Author: Enpatika.com

In shell scripting 0 is returned for success, and any other number for failure. In other languages such as Ruby, only nil and false are considered false, and any other value is considered true, so in Ruby both 1 and 0 would be considered true .

Because True is equal to 1 and False is equal to 0 , adding Booleans together is a quick way to count the number of True values.

The reason 1 is generally accepted as the integer equivalent to true is that it is the only other number besides 0 that is available in binary numbers, and boolean values are often stored and manipulated as bits . So, it is safest to use 1 as the integer value for boolean true in your code and 0 as false.

In the boolean type, there are only two possible values: true and false . We can have variables and expressions of type boolean, just has we have variables and expressions of type int and double. A boolean variable is only capable of storing either the value true or the value false.

Tcl has no separate Boolean type. Like in C, the integers 0 (false) and 1 (true—in fact any nonzero integer) are used .