Opcodes · stack · enabled

OP_IFDUP (0x73)

Duplicates the top item if it is not zero.

Verified
Stack in → out
x → x | x x
Since
Original Bitcoin script
Cost
Base instruction cost 100 plus bytes pushed (2025 VM limits).
Bitcoin status
Same in Bitcoin (BTC)

Example

OP_1 OP_IFDUP

Step through it opcode by opcode in Bitauth IDE, the in-browser BCH VM debugger.

Sources

  1. Libauth BCH_2023_05 opcodes (bch-2023-opcodes.ts)