API Change Statistics
The overall difference between API Levels 20 and 21 is approximately 6.51%.
Total of Differences, by Number and Type
The table below lists the numbers of program elements (packages, classes, constructors, methods, and fields) that were added, changed, or removed. The table includes only the highest-level program elements — that is, if a class with two methods was added, the number of methods added does not include those two methods, but the number of classes added does include that class.
| Type | Additions | Changes | Removals | Total |
|---|---|---|---|---|
| Packages | 14 | 57 | 1 | 72 |
| Classes and Interfaces | 147 | 360 | 0 | 507 |
| Constructors | 98 | 3 | 1 | 102 |
| Methods | 770 | 117 | 29 | 916 |
| Fields | 1150 | 75 | 2 | 1227 |
| Total | 2179 | 612 | 33 | 2824 |
Changed Packages, Sorted by Percentage Difference
* See Calculation of Change Percentages, below.
Changed Classes and Interfaces, Sorted by Percentage Difference
* See Calculation of Change Percentages, below.
Calculation of Change Percentages
The percent change statistic reported for all elements in the "to" API Level specification is defined recursively as follows:
Percentage difference = 100 * (added + removed + 2*changed)
-----------------------------------
sum of public elements in BOTH APIs
where added is the number of packages added, removed is the number of packages removed, and changed is the number of packages changed.
This definition is applied recursively for the classes and their program elements, so the value for a changed package will be less than 1, unless every class in that package has changed.
The definition ensures that if all packages are removed and all new packages are
added, the change will be 100%.