新人 JavaScript 求助语法问题

function sleepPromise() {
    return new Promise((resolve, reject) => {
        setTimeout(() => {
            console.log("promise")
        }, 1000)
    })
}

sleepPromise() // 这里没有分号

    (function () {
        console.log("hhh")
    })()

为啥调用 sleepPromise()的时候不加分号，就会跑不起来，加了分号就可以了

PS C:\Users\lala\Downloads> node c.js
C:\Users\lala\Downloads\c.js:11
    (function () {
    ^

TypeError: sleepPromise(...) is not a function
    at Object.<anonymous> (C:\Users\lala\Downloads\c.js:11:5)
    at Module._compile (node:internal/modules/cjs/loader:1105:14)
    at Object.Module._extensions..js (node:internal/modules/cjs/loader:1159:10)
    at Module.load (node:internal/modules/cjs/loader:981:32)
    at Function.Module._load (node:internal/modules/cjs/loader:822:12)
    at Function.executeUserEntryPoint [as runMain] (node:internal/modules/run_main:77:12)
    at node:internal/main/run_main_module:17:47

加了分号之后

function sleepPromise() {
    return new Promise((resolve, reject) => {
        setTimeout(() => {
            console.log("promise")
        }, 1000)
    })
}

sleepPromise(); // 这里有分号

    (function () {
        console.log("hhh")
    })()

PS C:\Users\lala\Downloads> node c.js
hhh
promise

我会 C ，但是不会 JavaScript ，求指教，感谢！