OP_0NOTEQUAL

INFO

Opcode number: 146
Byte representation: 0x92
Short description: Pop the top item and push 1 if the top item is not zero; otherwise, push an empty array.

OP_0NOTEQUAL pops the top item and checks whether it is not zero. If the item is non-zero, it pushes 1 (true) onto the stack. If the item is zero (or an empty array), it pushes an empty array (false).

Operation

1. Pop the top item.
2. If the item is zero, push an empty array (false) onto the stack.
3. If the item is non-zero, push 1 (true) onto the stack.

Notes

• If the stack is empty when OP_0NOTEQUAL is executed, the script will fail.

Examples

Example 1: Checking a zero value

# ASM script
OP_PUSHBYTES_2 0000 OP_0NOTEQUAL

# Raw script
02000092

# Stack (before OP_0NOTEQUAL)
0000  # top

# Stack (after OP_0NOTEQUAL)
[]  # false (empty array, as the input was zero)

Example 2: Checking a non-zero value

# ASM script
OP_2 OP_0NOTEQUAL

# Raw script
5292

# Stack (before OP_0NOTEQUAL)
2  # top

# Stack (after OP_0NOTEQUAL)
1  # true, as the input was non-zero