ชนิด input: text, password, email, number และ tel

องค์ประกอบ input

<input type="text">      <!-- single-line text -->
<input type="password"> <!-- masked text -->
<input type="email">    <!-- email address -->
<input type="number">   <!-- numeric -->
<input type="tel">      <!-- phone number -->

type=text

<label for="username">Username</label>
<input
  type="text"
  id="username"
  name="username"
  placeholder="e.g. jane_doe"
  maxlength="50"
  autocomplete="username"
>

type=password

<label for="pwd">Password</label>
<input
  type="password"
  id="pwd"
  name="password"
  minlength="8"
  autocomplete="current-password"
  required
>
<!-- Browser may offer to save/fill the password -->
<!-- autocomplete="new-password" for registration forms -->

type=email

<label for="email">Email</label>
<input
  type="email"
  id="email"
  name="email"
  placeholder="you@example.com"
  autocomplete="email"
  required
>
<!-- Mobile: shows @ on keyboard -->
<!-- Browser validates basic email format on submit -->

type=number

<label for="qty">Quantity</label>
<input
  type="number"
  id="qty"
  name="quantity"
  min="1"
  max="100"
  step="1"
  value="1"
>
<!-- min, max, step control allowed values -->
<!-- Mobile: shows numeric keypad -->
<!-- Note: only integers with step=1; decimals need step="0.01" -->

type=tel

<label for="phone">Phone number</label>
<input
  type="tel"
  id="phone"
  name="phone"
  placeholder="+1 (555) 555-0100"
  pattern="[+][0-9 ()-]{7,20}"
  autocomplete="tel"
>
<!-- Mobile: shows phone keypad -->
<!-- No built-in validation — phone formats vary globally -->
<!-- Use pattern attribute for format validation -->

แอตทริบิวต์ name สำคัญอย่างยิ่ง

<form action="/search">
  <!-- Without name, the field is NOT sent with the form -->
  <input type="text" name="q" placeholder="Search">
  <button type="submit">Search</button>
</form>
<!-- Submits: /search?q=your+search+term -->
<!-- name="q" → the key in the submitted data -->

Placeholder เทียบกับ Label

<!-- BAD: placeholder as label -->
<input type="text" placeholder="Enter your name">

<!-- GOOD: label + helpful placeholder -->
<label for="name">Full name</label>
<input type="text" id="name" name="name" placeholder="e.g. Jane Smith">
<!-- Placeholder disappears on typing — screen readers often skip it -->

value และ defaultValue

<input type="text" name="country" value="United States">
<!-- Renders with 'United States' pre-filled -->

<input type="number" name="qty" value="1" min="1" max="10">
<!-- Default quantity of 1 -->

disabled และ readonly

<input type="text" value="Fixed value" readonly>
<!-- readonly: user can see and select text, but not edit it -->
<!-- Value IS submitted with the form -->

<input type="text" value="Disabled" disabled>
<!-- disabled: user cannot interact with it at all -->
<!-- Value is NOT submitted with the form -->
<!-- NOT in tab order -->

ค่าการเติมข้อมูลอัตโนมัติของอินพุต

<input type="text" name="name" autocomplete="name">
<input type="email" name="email" autocomplete="email">
<input type="tel" name="phone" autocomplete="tel">
<input type="text" name="street" autocomplete="address-line1">
<input type="text" name="city" autocomplete="address-level2">
<input type="text" name="zip" autocomplete="postal-code">
<input type="password" autocomplete="new-password">

ตรวจสอบความเข้าใจ

ทบทวน: ชนิดอินพุต