ifeq : jump if zero : index : visitJumpInsn()

Description
ifeq pops the top int off the operand stack. If the int equals zero, execution branches to the address (pc + branchoffset), where pc is the address of the ifeq opcode in the bytecode and branchoffset is a 16-bit signed integer parameter following the ifeq opcode in the bytecode. If the int on the stack does not equal zero, execution continues at the next instruction.

If you are using Jasmin, branchoffset is computed for you from the address of <label>.
Example
    iload_1         ; push the int value in local variable 1 onto the stack
    ifeq Label      ; if the value of local variable 1 is zero, jump to Label
    return          ; return if local variable 1 is nonzero
Label:
    ; execution continues here if local variable 1 equals zero...
Notes
Addresses are measured in bytes from the start of the bytecode (i.e. address 0 is the first byte in the bytecode of the currently executing method).
See also
ifnull iflt ifle ifne ifnonnull ifgt ifge
Stack
Before After
value ...
... ...
Bytecode
Type Description
u1 ifeq opcode = 0x99 (153)
s2 branchoffset