call

(module
 ;; 从环境中导入 `greet` 函数
 (import "env" "greet" (func $greet))
 (func
 ;; 调用导入的 `greet` 函数
 call $greet
 )
 ;; 当模块启动时,自动运行第一个函数
 (start 1)
)

const url = "{%wasm-url%}";
await WebAssembly.instantiateStreaming(fetch(url), {
 env: {
 greet: function () {
 console.log("你好");
 // 期望的输出:"你好"
 },
 },
});

(module
 ;; 计算一个数的阶乘
 (func $fac (export "fac") (param $x i64) (result i64)
 ;; 用参数 $x 和 1 调用 `fac-aux` 函数
 (return_call $fac-aux (local.get $x) (i64.const 1))
 )
 ;; 计算阶乘
 (func $fac-aux (param $x i64) (param $r i64) (result i64)
 ;; 如果 $x 等于零,则返回聚集的结果 $r
 (if (result i64) (i64.eqz (local.get $x))
 (then (return (local.get $r)))
 (else
 ;; 否则,用 $x-1 和 $x*$r 递归调用 `fac-aux`
 (return_call $fac-aux
 (i64.sub (local.get $x) (i64.const 1))
 (i64.mul (local.get $x) (local.get $r))
 )
 )
 )
 )
)

const url = "{%wasm-url%}";
const { instance } = await WebAssembly.instantiateStreaming(fetch(url));
const result = instance.exports.fac(5n);
console.log(result);
// 期望的输出:120n

call $greet

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This page was last modified on ⁨2025年4月22日⁩ by MDN contributors.