The following operators serve to compare some subexpressions when you want to obtain a boolean value result. Each of the mentioned signs can be used. These signs can be used more times in one expression. In such a case you can express priority of comparisons by parentheses.
Important  

If you choose the

Greater than
Each of the two signs below can be used to compare expressions consisting of numeric, date and string data types. Both data types in the expressions must be comparable. The result can depend on the order of the two expressions if they are of different data types.
>
.gt.
boolean a = 4 > 3; a = "dog" > "cat"; if ( date1 > date2 ) {}
Greater than or equal to
Each of the three signs below can be used to compare expressions consisting of the numeric, date and string data types. Both data types in the expressions must be comparable. The result can depend on the order of the two expressions if they are of different data types.
>=
=>
.ge.
boolean a = 3.5 >= 3.5; a = "ls" >= "lsof"; a = date1 >= date2;
Less than
Each of the two signs below can be used to compare expressions consisting of numeric, date and string data types. Both data types in the expressions must be comparable. The result can depend on the order of the two expressions if they are of different data types.
<
.lt.
Less than or equal to
Each of the three signs below can be used to compare expressions consisting of the numeric, date and string data types. Both data types in the expressions must be comparable. The result can depend on the order of the two expressions if they are of different data types.
<=
=<
.le.
int a = 7L < 8L; if ( "awk" < "java" ) {} a = date1 < date2;
Equal to
Each of the two signs below can be used to compare expressions of any data type. Both data types in the expressions must be comparable. The result can depend on the order of the two expressions if they are of different data types.
==
.eq.
if( 5 == 5 ) {}
Not equal to
Each of the three signs below can be used to compare expressions of any data type. Both data types in the expressions must be comparable. The result can depend on the order of the two expressions if they are of different data types.
!=
<>
.ne.
if ( 9 != 8 ) {}
Matches regular expression
The operator serves to compare string and some regular expression.
It returns true
, if the whole string matches the regular expression,
otherwise returns false
.
If the right operand is null
, operator fails.
boolean b = "cat" ~= "[az]{3}";
~=
.regex.
boolean b1 = "new bookcase" ~= ".*book.*"; // true boolean b2 = "new bookcase" ~= "book"; // false boolean b3 = "new bookcase" ~= null; // fails
Contains regular expression
The operator serves to compare string and some regular expression.
It returns true
, if the string contains a substring
that matches the regular expression, otherwise returns false
.
?=
boolean b = "miredo" ?= "redo";