Solid.js vs Svelte 4 - JavaScript 框架语法对比

响应式

声明状态

Solid.js

import { createSignal } from "solid-js";

export default function Name() {
  const [name] = createSignal("张三");

  return <h1>你好 {name()}</h1>;
}

Svelte 4

<script>
  let name = "张三";
</script>

<h1>你好 {name}</h1>

更新状态

Solid.js

import { createSignal } from "solid-js";

export default function Name() {
  const [name, setName] = createSignal("张三");
  setName("李四");

  return <h1>你好 {name()}</h1>;
}

Svelte 4

<script>
  let name = "张三";
  name = "李四";
</script>

<h1>你好 {name}</h1>

计算属性

Solid.js

import { createSignal } from "solid-js";

export default function DoubleCount() {
  const [count] = createSignal(10);
  const doubleCount = () => count() * 2;

  return <div>{doubleCount()}</div>;
}

Svelte 4

<script>
  let count = 10;
  $: doubleCount = count * 2;
</script>

<div>{doubleCount}</div>

模板语法

最简模板

Solid.js

export default function HelloWorld() {
  return <h1>你好，世界</h1>;
}

Svelte 4

<h1>你好，世界</h1>

样式

Solid.js

import "./style.css";

export default function CssStyle() {
  return (
    <>
      <h1 class="title">我是红色的</h1>
      <button style={{ "font-size": "10rem" }}>我是一个按钮</button>
    </>
  );
}

Svelte 4

<h1 class="title">我是红色的</h1>
<button style="font-size: 10rem;">我是一个按钮</button>

<style>
  .title {
    color: red;
  }
</style>

DOM循环

Solid.js

import { For } from "solid-js";

export default function Colors() {
  const colors = ["红", "绿", "蓝"];

  return (
    <ul>
      <For each={colors}>{(color) => <li>{color}</li>}</For>
    </ul>
  );
}

Svelte 4

<script>
  const colors = ["红", "绿", "蓝"];
</script>

<ul>
  {#each colors as color (color)}
    <li>{color}</li>
  {/each}
</ul>

点击事件

Solid.js

import { createSignal } from "solid-js";

export default function Counter() {
  const [count, setCount] = createSignal(0);

  function incrementCount() {
    setCount(count() + 1);
  }

  return (
    <>
      <p>计数器: {count()}</p>
      <button onClick={incrementCount}>+1</button>
    </>
  );
}

Svelte 4

<script>
  let count = 0;

  function incrementCount() {
    count++;
  }
</script>

<p>计数器: {count}</p>
<button on:click={incrementCount}>+1</button>

DOM引用

Solid.js

import { onMount } from "solid-js";

export default function InputFocused() {
  let inputElement;

  onMount(() => inputElement.focus());

  return <input ref={inputElement} type="text" />;
}

Svelte 4

<script>
  import { onMount } from "svelte";

  let inputElement;

  onMount(() => {
    inputElement.focus();
  });
</script>

<input bind:this={inputElement} />

条件渲染

Solid.js

import { createSignal, Switch, Match } from "solid-js";

const TRAFFIC_LIGHTS = ["红灯", "黄灯", "绿灯"];

export default function TrafficLight() {
  const [lightIndex, setLightIndex] = createSignal(0);

  const light = () => TRAFFIC_LIGHTS[lightIndex()];

  function nextLight() {
    setLightIndex((lightIndex() + 1) % TRAFFIC_LIGHTS.length);
  }

  return (
    <>
      <button onClick={nextLight}>下一个灯</button>
      <p>现在亮着的是: {light()}</p>
      <p>
        你应该
        <Switch>
          <Match when={light() === "红灯"}>
            <span>停下</span>
          </Match>
          <Match when={light() === "黄灯"}>
            <span>慢行</span>
          </Match>
          <Match when={light() === "绿灯"}>
            <span>赶紧走</span>
          </Match>
        </Switch>
      </p>
    </>
  );
}

Svelte 4

<script>
  const TRAFFIC_LIGHTS = ["红灯", "黄灯", "绿灯"];
  let lightIndex = 0;

  $: light = TRAFFIC_LIGHTS[lightIndex];

  function nextLight() {
    lightIndex = (lightIndex + 1) % TRAFFIC_LIGHTS.length;
  }
</script>

<button on:click={nextLight}>下一个灯</button>
<p>现在亮着的是: {light}</p>
<p>
  你应该
  {#if light === "红灯"}
    <span>停下</span>
  {:else if light === "黄灯"}
    <span>慢行</span>
  {:else if light === "绿灯"}
    <span>赶紧走</span>
  {/if}
</p>

生命周期

组件加载时

Solid.js

import { createSignal, onMount } from "solid-js";

export default function PageTitle() {
  const [pageTitle, setPageTitle] = createSignal("");

  onMount(() => {
    setPageTitle(document.title);
  });

  return <p>页面标题: {pageTitle()}</p>;
}

Svelte 4

<script>
  import { onMount } from "svelte";
  let pageTitle = "";
  onMount(() => {
    pageTitle = document.title;
  });
</script>

<p>页面标题: {pageTitle}</p>

组件卸载时

Solid.js

import { createSignal, onCleanup } from "solid-js";

export default function Time() {
  const [time, setTime] = createSignal(new Date().toLocaleTimeString());

  const timer = setInterval(() => {
    setTime(new Date().toLocaleTimeString());
  }, 1000);

  onCleanup(() => clearInterval(timer));

  return <p>当前时间: {time()}</p>;
}

Svelte 4

<script>
  import { onDestroy } from "svelte";

  let time = new Date().toLocaleTimeString();

  const timer = setInterval(() => {
    time = new Date().toLocaleTimeString();
  }, 1000);

  onDestroy(() => clearInterval(timer));
</script>

<p>当前时间: {time}</p>

组件组合

组件Props传参

Solid.js

import UserProfile from "./UserProfile.jsx";

export default function App() {
  return (
    <UserProfile
      name="张三"
      age={20}
      favouriteColors={["green", "blue", "red"]}
      isAvailable
    />
  );
}

Svelte 4

<script>
  import UserProfile from "./UserProfile.svelte";
</script>

<UserProfile
  name="张三"
  age={20}
  favouriteColors={["green", "blue", "red"]}
  isAvailable
/>

向父组件emit事件

Solid.js

import { createSignal } from "solid-js";
import AnswerButton from "./AnswerButton.jsx";

export default function App() {
  const [isHappy, setIsHappy] = createSignal(true);

  function onAnswerNo() {
    setIsHappy(false);
  }

  function onAnswerYes() {
    setIsHappy(true);
  }

  return (
    <>
      <p>你快乐吗?</p>
      <AnswerButton onYes={onAnswerYes} onNo={onAnswerNo} />
      <p style={{ "font-size": "50px" }}>{isHappy() ? "😀" : "😥"}</p>
    </>
  );
}

Svelte 4

<script>
  import AnswerButton from "./AnswerButton.svelte";

  let isHappy = true;

  function onAnswerNo() {
    isHappy = false;
  }

  function onAnswerYes() {
    isHappy = true;
  }
</script>

<p>你快乐吗?</p>
<AnswerButton on:yes={onAnswerYes} on:no={onAnswerNo} />
<p style="font-size: 50px;">{isHappy ? "😀" : "😥"}</p>

slot插槽

Solid.js

import FunnyButton from "./FunnyButton.jsx";

export default function App() {
  return <FunnyButton>点我!</FunnyButton>;
}

Svelte 4

<script>
  import FunnyButton from "./FunnyButton.svelte";
</script>

<FunnyButton>点我!</FunnyButton>

slot插槽内容

Solid.js

import FunnyButton from "./FunnyButton.jsx";

export default function App() {
  return (
    <>
      <FunnyButton />
      <FunnyButton>这是传到slot的内容!</FunnyButton>
    </>
  );
}

Svelte 4

<script>
  import FunnyButton from "./FunnyButton.svelte";
</script>

<FunnyButton />
<FunnyButton>这是传到slot的内容!</FunnyButton>

上下文

Solid.js

import { createSignal } from "solid-js";

import { UserContext } from "./UserContext";
import UserProfile from "./UserProfile";

export default function App() {
  const [user, setUser] = createSignal({
    id: 1,
    username: "abcdefg",
    email: "[email protected]",
  });

  function updateUsername(newUsername) {
    setUser({ ...user(), username: newUsername });
  }

  return (
    <>
      <h1>欢迎回来, {user().username}</h1>
      <UserContext.Provider value={[user, updateUsername]}>
        <UserProfile />
      </UserContext.Provider>
    </>
  );
}

Svelte 4

<script>
  import { setContext } from "svelte";
  import UserProfile from "./UserProfile.svelte";
  import createUserStore from "./createUserStore.js";

  const userStore = createUserStore({
    id: 1,
    username: "abcdefg",
    email: "[email protected]",
  });

  setContext("user", userStore);
</script>

<h1>欢迎回来, {$userStore.username}</h1>
<UserProfile />

表单输入

输入框

Solid.js

import { createSignal } from "solid-js";

export default function InputHello() {
  const [text, setText] = createSignal("你好世界");

  function handleChange(event) {
    setText(event.target.value);
  }

  return (
    <>
      <p>{text()}</p>
      <input value={text()} onInput={handleChange} />
    </>
  );
}

Svelte 4

<script>
  let text = "你好世界";
</script>

<p>{text}</p>
<input bind:value={text} />

复选框

Solid.js

import { createSignal } from "solid-js";

export default function IsAvailable() {
  const [isAvailable, setIsAvailable] = createSignal(false);

  function handleChange() {
    setIsAvailable((previousValue) => !previousValue);
  }

  return (
    <>
      <input
        id="is-available"
        type="checkbox"
        checked={isAvailable()}
        onChange={handleChange}
      />
      <label for="is-available">这是一个checkbox</label>
    </>
  );
}

Svelte 4

<script>
  let isAvailable = false;
</script>

<input id="is-available" type="checkbox" bind:checked={isAvailable} />
<label for="is-available">这是一个checkbox</label>

单选框

Solid.js

import { createSignal } from "solid-js";

export default function PickPill() {
  const [picked, setPicked] = createSignal("red");

  function handleChange(event) {
    setPicked(event.target.value);
  }

  return (
    <>
      <div>你选择了: {picked()}</div>
      <input
        id="blue-pill"
        checked={picked() === "blue"}
        type="radio"
        value="blue"
        onChange={handleChange}
      />
      <label for="blue-pill">蓝色</label>

      <input
        id="red-pill"
        checked={picked() === "red"}
        type="radio"
        value="red"
        onChange={handleChange}
      />
      <label for="red-pill">红色</label>
    </>
  );
}

Svelte 4

<script>
  let picked = "red";
</script>

<div>你选择了: {picked}</div>

<input id="blue-pill" bind:group={picked} type="radio" value="blue" />
<label for="blue-pill">蓝色</label>

<input id="red-pill" bind:group={picked} type="radio" value="red" />
<label for="red-pill">红色</label>

选择器

Solid.js

import { createSignal, For } from "solid-js";

const colors = [
  { id: 1, text: "红" },
  { id: 2, text: "蓝" },
  { id: 3, text: "绿" },
  { id: 4, text: "灰", isDisabled: true },
];

export default function ColorSelect() {
  const [selectedColorId, setSelectedColorId] = createSignal(2);

  function handleChange(event) {
    setSelectedColorId(event.target.value);
  }

  return (
    <select value={selectedColorId()} onChange={handleChange}>
      <For each={colors}>
        {(color) => (
          <option value={color.id} disabled={color.isDisabled}>
            {color.text}
          </option>
        )}
      </For>
    </select>
  );
}

Svelte 4

<script>
  let selectedColorId = 2;

  const colors = [
    { id: 1, text: "红" },
    { id: 2, text: "蓝" },
    { id: 3, text: "绿" },
    { id: 4, text: "灰", isDisabled: true },
  ];
</script>

<select bind:value={selectedColorId}>
  {#each colors as color}
    <option value={color.id} disabled={color.isDisabled}>
      {color.text}
    </option>
  {/each}
</select>

Web应用特性

渲染应用

Solid.js

<!doctype html>
<html>
  <body>
    <div id="app"></div>
    <script type="module" src="./main.jsx"></script>
  </body>
</html>

Svelte 4

<!doctype html>
<html>
  <body>
    <div id="app"></div>
    <script type="module" src="./app.js"></script>
  </body>
</html>

fetch获取数据

Solid.js

import { createResource, For, Switch, Match } from "solid-js";

async function fetchUsers() {
  return (await fetch("https://randomuser.me/api/?results=3")).json();
}

export default function App() {
  const [data] = createResource(fetchUsers);
  const users = () => data()?.results;

  return (
    <Switch>
      <Match when={data.loading}>
        <p>正在获取用户信息……</p>
      </Match>
      <Match when={data.error}>
        <p>获取用户信息出错</p>
      </Match>
      <Match when={users()}>
        <ul>
          <For each={users()}>
            {(user) => (
              <li>
                <img src={user.picture.thumbnail} alt="user" />
                <p>
                  {user.name.first} {user.name.last}
                </p>
              </li>
            )}
          </For>
        </ul>
      </Match>
    </Switch>
  );
}

Svelte 4

<script>
  import useFetchUsers from "./useFetchUsers";

  const { isLoading, error, data: users } = useFetchUsers();
</script>

{#if $isLoading}
  <p>正在获取用户信息……</p>
{:else if $error}
  <p>获取用户信息出错</p>
{:else if $users}
  <ul>
    {#each $users as user}
      <li>
        <img src={user.picture.thumbnail} alt="user" />
        <p>
          {user.name.first}
          {user.name.last}
        </p>
      </li>
    {/each}
  </ul>
{/if}

响应式 #

声明状态 #

Solid.js

Svelte 4

更新状态 #

Solid.js

Svelte 4

计算属性 #

Solid.js

Svelte 4

模板语法 #

最简模板 #

Solid.js

Svelte 4

样式 #

Solid.js

Svelte 4

DOM循环 #

Solid.js

Svelte 4

点击事件 #

Solid.js

Svelte 4

DOM引用 #

Solid.js

Svelte 4

条件渲染 #

Solid.js

Svelte 4

生命周期 #

组件加载时 #

Solid.js

Svelte 4

组件卸载时 #

Solid.js

Svelte 4

组件组合 #

组件Props传参 #

Solid.js

Svelte 4

向父组件emit事件 #

Solid.js

Svelte 4

slot插槽 #

Solid.js

Svelte 4

slot插槽内容 #

Solid.js

Svelte 4

上下文 #

Solid.js

Svelte 4

表单输入 #

输入框 #

Solid.js

Svelte 4

复选框 #

Solid.js

Svelte 4

单选框 #

Solid.js

Svelte 4

选择器 #

Solid.js

Svelte 4

Web应用特性 #

渲染应用 #

Solid.js

Svelte 4

fetch获取数据 #

Solid.js

Svelte 4

响应式

声明状态

更新状态

计算属性

模板语法

最简模板

样式

DOM循环

点击事件

DOM引用

条件渲染

生命周期

组件加载时

组件卸载时

组件组合

组件Props传参

向父组件emit事件

slot插槽

slot插槽内容

上下文

表单输入

输入框

复选框

单选框

选择器

Web应用特性

渲染应用

fetch获取数据