Tcl - Logical Operators


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Following table shows all the logical operators supported by Tcl language. Assume variable A holds 1 and variable B holds 0, then −

Operator Description Example
&& Called Logical AND operator. If both the operands are non-zero, then condition becomes true. (A && B) is false.
|| Called Logical OR Operator. If any of the two operands is non-zero, then condition becomes true. (A || B) is true.
! Called Logical NOT Operator. Use to reverses the logical state of its operand. If a condition is true then Logical NOT operator will make false. !(A && B) is true.

Example

Try the following example to understand all the logical operators available in Tcl language −

#!/usr/bin/tclsh

set a  5
set b 20

if { $a && $b } {
   puts "Line 1 - Condition is true\n"
}
if { $a || $b } {
   puts "Line 2 - Condition is true\n"
}
# lets change the value of  a and b 
set a  0
set b 10
if { $a && $b } {
   puts "Line 3 - Condition is true\n"
} else {
   puts "Line 3 - Condition is not true\n" 
}
if { !($a && $b) } {
   puts "Line 4 - Condition is true\n" 
}

When you compile and execute the above program, it produces the following result −

Line 1 - Condition is true

Line 2 - Condition is true

Line 3 - Condition is not true

Line 4 - Condition is true
tcl_operators.htm
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