index.md

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title: WebAssembly control flow instructions
slug: WebAssembly/Reference/Control_flow

---

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WebAssembly control flow instructions.

• block

  • : Creates a label that can later be branched out of with a br.

• br

  • : Branches to a loop or block.

• call

  • : Calls a function.

• drop

  • : Pops a value from the stack, and discards it.

• end

  • : Can be used to end a block, loop, if, or else.

• if...else

  • : Executes a statement if the last item on the stack is true (1).

• loop

  • : Creates a label that can later be branched to with a br.

• nop

  • : Does nothing.

• return

  • : Returns from a function.

• select

  • : Selects one of its first two operands based on a boolean condition.

• unreachable

  • : Denotes a point in code that should not be reachable.