OP_ENDIF

INFO

Opcode number: 104
Byte representation: 0x68
Short description: Ends a conditional block.

OP_ENDIF is used to conclude conditional structures in Bitcoin scripting initiated by OP_IF or OP_NOTIF. It denotes the end of the conditional execution paths and allows the script to continue with any subsequent commands outside of the conditional block.

Operation

1. Continue executing the following opcodes in the script after the OP_ENDIF.

Note that OP_ENDIF itself does not directly cause any action other than marking the end of the conditional segment. Its presence ensures that the preceding conditional logic (whether that's an OP_IF, OP_NOTIF, or an accompanying OP_ELSE) has been properly closed.

Notes

• Each OP_IF or OP_NOTIF must have a corresponding OP_ENDIF. Failing to do so will render the script invalid.
• A script can have nested OP_IF/OP_NOTIF structures, but each of them must be properly closed with their own OP_ENDIF.
• A script with an OP_ENDIF without a preceding OP_IF or OP_NOTIF is also invalid.

Examples

Example 1

The following script leaves 2 on the stack since the condition (1) is true.

# ASM script
OP_1 OP_IF OP_2 OP_ENDIF

# Raw script
516368

# Final stack
2

Example 2

The following script with nested conditionals leaves 4 on the stack since both conditions (1) are true.

# ASM script
OP_1 OP_IF 
    OP_1 OP_IF 
        OP_4 
    OP_ENDIF
OP_ENDIF

# Raw script
51516351546868

# Final stack
4