OP_OVER

INFO

Opcode number: 120
Byte representation: 0x78
Short description: Duplicates the second item from the top of the stack.

OP_OVER is used to duplicate the second item from the stack (i.e., the value one over from the top).

Operation

1. Duplicate the item one over from the top of the stack, i.e., the second stack item.
2. Push this duplicate onto the stack.

Notes

• This opcode is part of a family of opcodes (OP_OVER, OP_2OVER, OP_DUP, and a few others) designed for duplication of stack items.
• If there are fewer than two items on the stack when OP_OVER is executed, the script will fail.

Examples

Example 1

Duplicating the stack item one over from the top (i.e., the second stack item) with two total items:

# ASM script
OP_1 OP_2 OP_OVER

# Raw script
515278

# Stack (before OP_OVER)
2
1

# Stack (after OP_OVER)
1
2
1

Example 2

Duplicating the stack item one over from the top (i.e., the second stack item) with four total items:

# ASM script
OP_1 OP_2 OP_3 OP_4 OP_OVER

# Raw script
5152535478

# Stack (before OP_OVER)
4
3
2
1

# Stack (after OP_OVER)
3
4
3
2
1