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''Logical Operators'' are also known as ''Boolean Operators'' because they evaluate parts of an expression and return a ''true'' or ''false'' value, allowing desicions to be made about how a script should proceed.

Perhaps the best way The first step to understand understanding how logical operators work is to construct a sentence rather than to look at a script example right away. Let's assume we want need to check some aspect of two variables named x $var1 and y$var2. Our sentence might read:

''If x $var is less than 10 25 AND y $var2 is greater than 20 45 display a message.''

if ((x $var1 < 1025) && (y $var2 > 2045)document.write ("Message")echo 'Our expression is true';

Similarly , if our sentence was to read:

''If x $var1 is less than 10 25 OR y $var2 is greater than 20 45 display a message.''

if ((x $var1 < 1025) || (y $var2 > 2045)document.write ("Message")echo 'Our expression is true';

The final Logical Operator is the NOT operator which simply inverts the result of an expression. The ! character represents the NOT operatoer operater and can be used as follows:

!(10 > 1) // retruns returns ''false'' because we have inverted the result with the logical NOT