OP_1NEGATE ​

The OP_1NEGATE opcode will push 0x81 (representing -1 in the context of script execution) onto the stack. This opcode utilizes the minimally encoded integers format.

Examples ​

Example 1 ​

# ASM script
OP_1NEGATE OP_1NEGATE

# Raw script
4f4f

# Final stack
-1
-1

Example 2 ​

# ASM script
OP_8 OP_1NEGATE OP_ADD

# Raw script
584f93

# Final stack
7

In the first example, we have a script with two OP_1NEGATE opcodes. After execution, we have two -1s on the stack. In the second example, we add another opcode, OP_ADD, to the script. The OP_ADD opcode will remove the two top items from the stack, add them together, and then push the result back onto the stack. 8 + (-1) results in 7, which is then pushed onto the stack.