example <param1> <param2> ...Stack
Before | After |
item1 | item2 |
item2 | item1 |
... | ... |
This page explains the format for instruction reference pages.
The first line on a reference page lists the name of an instruction and gives a brief synopsis of the instruction.
The 'Jasmin Syntax' section indicates the Jasmin assembler syntax for the instruction. In the example above, the instruction is shown with two parameters, one called <param1> and the other called <param2>. The 'Jasmin Syntax' also includes additional notes for Jasmin users.
The 'Stack' section describes the effect that the instruction has on the operand stack. It shows a symbolic representation of the stack state before and after the execution of the instruction. Each row in the tables represents a one-word entry on the stack. The first row represents the top of the stack. In the example above, its clear that the order of the top two words on the stack is reversed by the instruction.
The section you are reading is the 'Description' section, which gives details of how the instruction works and what its side effects are.
Example
; This section often contains examples illustrating how ; an instruction is used. ; Examples are written using the Jasmin assembler syntax.Exceptions
This section lists any exceptions generated by the instruction at runtime, and explains what causes each exception.
Bytecode
The 'Bytecode' section gives details on how the instruction is laid out in the bytecode of a class file. It shows a table listing the opcode for the instruction, as well as any additional parameters that follow the opcode in bytecode.
Type | Description |
u1 | This line usually shows the opcode for the instruction |
u1 | A 'u1' field is an unsigned 1-byte integer field |
u2 | A 'u2' field is an unsigned 2-byte integer field |
u4 | A 'u4' field is an unsigned 4-byte integer field |
s1 | A 's1' field is a signed 1-byte integer field |
s2 | A 's2' field is a signed 2-byte short integer field |
s4 | A 's4' field is a signed 4-byte integer field |
The 'See Also' section lists related instructions that you should look at.
Notes
The 'Notes' section gives additional details that you should be aware of.