How to printf a Java String. To use the Java String printf method to format output text, follow these rules:. Use %s as the printf String specifier in the text string being formatted.; Use %S as the ...

How to format a Java double with printf?. To format a Java float or double with printf, follow the same steps to format an integer with the following two addendums:. The conversion specifier for a ...

When you write String::toUpperCase, Java binds each element of the stream (String object) to the toUpperCase() method. This means String::toUpperCase is interpreted as s -> s.toUpperCase() , where ...