Course of Raku / Essentials / Control flow essentials / Conditional checks

Comparing numbers

To compare two numbers, use the following operators. All of them are quite obvious if you are familiar with other programming languages.

== | Equal != | Not equal < | Less than <= | Less than or equal > | Greater than >= | Greater than or equal

Approximately-equal

In addition to standard operators, Raku adds the approximately-equal operator =~=, which compares the numbers approximately. Its result is True if the two numbers are relatively close to each other. The maximum relative difference must not exceed the built-in value $*TOLERANCE, which is equal to 1e-15.

Unicode versions

Some of the above operators have their Unicode equivalents:

!= | ≠ <= | ≤ >= | ≥ =~= | ≅

Examples

Some examples with the operators that compare numbers:

say 10 == 10; # True
say 10 != 10; # False

say 15 < 10;  # False
say 10 <= 10; # True
say 16 > 10;  # True
say 10 >= 14; # False

say 1.000000000000000000000001 =~= 1.000000000000000000000002; # True
say 2e17 + 1 =~= 2e17 + 100; # True

Note that the number 1.000000000000000000000001 is a Rat number, so you do not lose precision in an expression with a close number 1.000000000000000000000002. The last example with 2e17 operates with Num numbers, which have restricted precision.

Course navigation

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