Equal

The eq instructions, short for equal, check if two numbers are equal. If both numbers are equal 1 will be pushed on to the stack, otherwise 0 will be pushed on to the stack.

Similarly, the eqz instructions check if a number is equal to zero, the eqz instructions are only available for the integer types and not for the floating point types.

Try it

(module
  (import "env" "log_bool" (func $log_bool (param i32)))
  (func $main
    ;; load `10` and `2` onto the stack
    i32.const 10
    i32.const 2

    i32.eq ;; check if `10` is equal to `2`
    call $log_bool ;; log the result
  )
  (start $main)
)

const url = "{%wasm-url%}";

function log_bool(value) {
  console.log(Boolean(value));
  // Expected output: false
}

await WebAssembly.instantiateStreaming(fetch(url), {
  env: { log_bool },
});

Syntax

wasm

;; load 2 numbers on to the stack
local.get $num
i32.const 2

;; check if $num is equal to '2'
i32.eq

;; if $num is equal to `2`, `1` will be pushed on to the stack,
;; otherwise `0` will be pushed on to the stack.

Instruction	Binary opcode
`i32.eqz`	`0x45`
`i32.eq`	`0x46`
`i64.eqz`	`0x50`
`i64.eq`	`0x51`
`f32.eq`	`0x5b`
`f64.eq`	`0x61`