Formatter class outputs the formatted output. It can format numbers, strings, and time and date. It operates in a manner similar to the C/C++ printf() function.
The most commonly used format function is:
Formatter format(String fmtString, Object ... args)
The fmtSring consists characters that are copied to the output buffer and the format specifiers.
A format specifier begins with a percent sign followed by the format conversion specifier. For example, the format specifier for floating-point data is %f
The format specifiers and the arguments are matched in order from left to right.