Nim - Case

Switch case is a common control flow statement provided by every language.

Nim Provides case statements. These are similar to if else conditional expressions

Nim case statement example

case expression evaluates to a value, and the value is matched with of statement and executes statements inside it.

Syntax

case conditional_expression:
  of "value":
      // statements;
  of "value":
      // statements;
  of "value":
      // statements;
  else:
      //default case statements;

conditional_expression is evaluated to ordinal value data types such as strings, bool, chars, and integers, value is compared with of value, and matched if statements are executed.

conditional_expression can be variable.

if no matching is found, the default else statement is executed.

let number = 10
case number:
of 1:
    echo "value is 1"
of 2:
    echo "value is 2"
of 2:
    echo "value is 3"
else:
    echo "value is not 1 or 2 or 3"

Output:

value is not 1 or 2 or 3

of the statement contains a range of values using two dots operator

let number = 100
case number:
of 1..9:
    echo "single digit"
of 10-99:
    echo "double digit"
of 100-999:
    echo "triple digit"
else:
    echo " 4 or more digits"

Output

triple digit

of statement can also contain multiple values separated by a comma.

let number = 'two'
case number:
of 'one", 'two':
    echo "one or two"
else:
    echo " Not one or two"

Output

one or two