69 - C++ LOGICAL OPERATORS

[SIZE=7][B]Logical Operator: &&[/B][/SIZE]
The [ICODE]and[/ICODE] logical operator is denoted by [ICODE]&&[/ICODE].
It returns [ICODE]true[/ICODE] if the condition on the left [I]and[/I] the condition on the right are both [ICODE]true[/ICODE]. Otherwise, it returns [ICODE]false[/ICODE].
Here’s the truth table:
[TABLE]
[TR]
[TH]a[/TH]
[TH]b[/TH]
[TH]a && b[/TH]
[/TR]
[TR]
[TD]false[/TD]
[TD]false[/TD]
[TD]false[/TD]
[/TR]
[TR]
[TD]false[/TD]
[TD]true[/TD]
[TD]false[/TD]
[/TR]
[TR]
[TD]true[/TD]
[TD]false[/TD]
[TD]false[/TD]
[/TR]
[TR]
[TD]true[/TD]
[TD]true[/TD]
[TD]true[/TD]
[/TR]
[/TABLE]

For instance:
[LIST]
[*][ICODE]( 1 < 2 && 2 < 3 )[/ICODE] returns [ICODE]true[/ICODE]
[*][ICODE]( 1 < 2 && 2 > 3 )[/ICODE] returns [ICODE]false[/ICODE]
[/LIST]
[B]Note:[/B] The keyword [ICODE]and[/ICODE] can also be used in the place of [ICODE]&&[/ICODE].

[SIZE=7][B]Logical Operator: II[/B][/SIZE]
The [ICODE]or[/ICODE] logical operator is denoted by [ICODE]||[/ICODE].
It returns [ICODE]true[/ICODE] when the condition on the left is [ICODE]true[/ICODE] [I]or[/I] the condition on the right is [ICODE]true[/ICODE]. Only one of them needs to be [ICODE]true[/ICODE].
Here’s the truth table:
[TABLE]
[TR]
[TH]a[/TH]
[TH]b[/TH]
[TH]a || b[/TH]
[/TR]
[TR]
[TD]false[/TD]
[TD]false[/TD]
[TD]false[/TD]
[/TR]
[TR]
[TD]false[/TD]
[TD]true[/TD]
[TD]true[/TD]
[/TR]
[TR]
[TD]true[/TD]
[TD]false[/TD]
[TD]true[/TD]
[/TR]
[TR]
[TD]true[/TD]
[TD]true[/TD]
[TD]true[/TD]
[/TR]
[/TABLE]
For instance:
[LIST]
[*][ICODE]( 1 < 2 || 2 > 3 )[/ICODE] returns [ICODE]true[/ICODE]
[*][ICODE]( 1 > 2 || 2 > 3 )[/ICODE] returns [ICODE]false[/ICODE]
[/LIST]
[B]Note:[/B] The keyword [ICODE]or[/ICODE] can be used in the place of [ICODE]||[/ICODE].

[SIZE=7][B]Logical Operator: ![/B][/SIZE]
The [ICODE]not[/ICODE] logical operator is denoted by [ICODE]![/ICODE].
It reverses the [ICODE]bool[/ICODE] outcome of the expression that immediately follows.
Here’s the truth table:
[TABLE]
[TR]
[TH]a[/TH]
[TH]!a[/TH]
[/TR]
[TR]
[TD]false[/TD]
[TD]true[/TD]
[/TR]
[TR]
[TD]true[/TD]
[TD]false[/TD]
[/TR]
[/TABLE]
For instance:
[LIST]
[*][ICODE]( !true )[/ICODE] returns [ICODE]false[/ICODE]
[*][ICODE]( !false )[/ICODE] returns [ICODE]true[/ICODE]
[*][ICODE]( !(10 < 11) )[/ICODE] returns [ICODE]false[/ICODE]
[/LIST]
[B]Note:[/B] The keyword [ICODE]not[/ICODE] can be used in the place of [ICODE]![/ICODE].

[SIZE=7][B]Review[/B][/SIZE]
Awesome! In this mini-lesson, we’ve added more operators to our toolbox:
[LIST]
[*][ICODE]&&[/ICODE]: the [ICODE]and[/ICODE] logical operator
[*][ICODE]||[/ICODE]: the [ICODE]or[/ICODE] logical operator
[*][ICODE]![/ICODE]: the [ICODE]not[/ICODE] logical operator
[/LIST]