lowercase and uppercase

The lowercase and uppercase filters are used to convert alphabetic characters in a string to lowercase or uppercase. Each takes a single string argument, and each has precedence just higher than +.

lowercase

The lowercase filter converts its single string argument to lowercase:

    lowercase "ABC" == "abc"
    lowercase "Kasparov 1987" == "kasparov 1987"

The lowercase filter has higher precedence than plusstring:

   lowercase "Karpov"+ "Kasparov" == "karpovKasparov"

The lowercase filter matches whenever its argument matches.

uppercase

The uppercase filter converts its single string argument to uppercase:

    uppercase "abc" == "ABC"
    uppercase "Kasparov 1987" == "KASPAROV 1987"

The uppercase filter has higher precedence than plusstring:

   uppercase "Karpov"+ "Kasparov" == "KARPOVKasparov"

The uppercase filter matches whenever its argument matches.