Unnamed parameters

{{str sub new|1234567890|3|7}}

{{str sub new|1234567890|3|-3}}

{{str sub new|1234567890|3}}

{{str sub new|1234567890|12}}

Named parameters

{{Str sub new|s=abcd=fgh|i=3|j=7}}

Equivalent to:

{{#invoke:string|sub|s=abcd=fgh|i=3|j=7}}

Named parameters are required if the target string contains an equals sign, where unnamed or numbered parameters will not work as expected:

{{str sub new|abcd=fgh|3|7}}

{{str sub new|1=abcd=fgh|2=3|3=7}}