As far as I know, Java never updated the syntax for defining integral constants since JDK 1.2, which seems like ages before. To end that drought, Java 7 defines enhanced syntax for the following,

  • Numeric constants expressed as binary
  • Suffix to denote type as short or byte
  • Improved readability by use of underscores in integer constants

The above enhancements do not impact a seasoned developer much, nor they provide something out-of-this-world. The only benefit you get is improved readability and vanishing of minor hiccups when coding.

Binary Values

Before Java 7, in order to parse binary values one would write,

    int value = Integer.parseInt("10101010", 2);

This in addition to some extra code, also has performance impact besides making the value as a runtime constant than compile time constant. Thankfully, Java 7 introduces the concept of 0b< on the same lines as 0x for hexa-decimal values. Thus, the above code fragment in Java 7 would become,

    int value = 0b10101010;

The value is now a compile time constant and also, has no performance hit.

Short and Byte values

Java had several integral types such as short and byte, but no syntactical way to code the values directly in, as all numerical constant were treated as integers. Type-casting led to annoyance and discomfort during code and might also have led to limit-over-runs. With Java 7, assigning values for these integral types becomes easy as,

    byte b = 245y;


    short s = 65535s;

The above values just provide some syntactical sugar when coding and improves readability.

Underscores in values

A long binary, hexa-decimal or integral value becomes hard to read by human mind. If the number of digits increase figuring out the exact extant of the value at times gets difficult. Java 7 adds some real beauty for such use-cases by adding support to add underscores to integral values for improved readability. Thus a value of 2 GB, 2147483648 now may be expressed as,

    long twoGigabytes = 2_147_483_648L;

In my honest opinion, this is definitely a boon for mathematical and statistical developers who really had tough time understanding someone’s else code… err.. defined constants.

Hope this helps me, more than anyone else in remembering the new sugars! Happy Coding!