Branch if reference is null (wide index)

Format

ifnull_w

branchbyte1

branchbyte2

Forms

ifnull_w = 158 (0x9e)

Stack

…, value → …

Description

The value must be of type reference. It is popped from the operand stack. If the value is null, the unsigned bytes branchbyte1 and branchbyte2 are used to construct a signed 16-bit branchoffset, where branchoffset is (branchbyte1 « 8) | branchbyte2. Execution proceeds at that offset from the address of the opcode of this ifnull_w instruction. The target address must be that of an opcode of an instruction within the method that contains this ifnull_w instruction.

Otherwise, execution proceeds at the address of the instruction following this ifnull_w instruction.