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aload

retrieve object reference from local variable

Jasmin Syntax 


    aload <varnum>
or
    wide
    aload <varnum>
In the first form, <varnum> is an unsigned integer in the range 0 to 0xFF. In the second (wide) form, <varnum> is an unsigned integer in the range 0 to 0xFFFF.

Stack

Before

After
...
objectref

...
Description

Retrieves an object reference from a local variable and pushes it onto the operand stack. The aload instruction takes a single parameter, <varnum>, an unsigned integer which indicates which local variable to retrieve. The object reference in that local variable is retrieved and placed on the stack. <varnum> must be a valid local variable number in the current frame.

Example 



aload 1         ; push object reference in local variable 1 onto the stack
Bytecode

To access to local variables in the range 0-255, use:

Type

Description
u1
aload opcode = 0x19 (25)
u1
<varnum>
There is also a wide format for this instruction, which supports access to all local variables from 0 to 65535:

Type

Description
u1
wide opcode = 0xC4 (196)
u1
aload opcode = 0x19 (25)
u2
<varnum>
See Also

fload, iload, lload, dload, wide

Notes

If you use astore to store a returnAddress in a local variable, you cannot then use aload to retrieve the value of that local variable. Instead, if a local variable holds a returnAddress, your only choices are to (1) use ret to return to that address, or (2) use one of the store instructions to store some other value in the local variable.

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Java Virtual Machine, by Jon Meyer and Troy Downing, O'Reilly Associates