index.md

---

title: if...else
slug: WebAssembly/Reference/Control_flow/if...else

---

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The if statement executes a statement if the last item on the stack is true (1). If the condition is false (0), another statement can be executed

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Syntax

i32.const 0
(if
  (then
    ;; do something
  )
  (else
    ;; do something else
  )
)

Instruction	Binary opcode
if	0x04
else	0x05