31 - Use HTML5 to Require a Field
使用這個 input required 屬性,使用者就不能以空白提交資料
<form action="/submit-cat-photo">
<input type="text" placeholder="cat photo URL" required>
<button type="submit">Submit</button>
</form>
Submit
32 - Create a Set of Radio Buttons
每一個單選按鈕都應該嵌套在它自己的label(標簽)元素中。
注意:所有關聯的單選按鈕應該使用相同的name屬性。
參考資料
應該 <label></label>
像是單純顯示的文字,但和 input
又有點關係。看其他的範例,都是 label 裡面要再設定 for=""。因此我推測,如果將 input 放到 label 裡面 nesting,就可以省去這些設定
<form action="/submit-cat-photo">
<label> <input type="radio" name="indoor-outdoor"/>indoor</label>
<label><input type="radio" name="indoor-outdoor">outdoor</label>
<button type="submit">Submit</button>
</form>
33 - Create a Set of Checkboxes
<form action="/submit-cat-photo">
<label><input type="checkbox" name="personality"> 內向</label>
<label><input type="checkbox" name="personality"> 外向</label>
<label><input type="checkbox" name="personality"> 神經</label>
<input type="text" placeholder="cat photo URL" required>
<button type="submit">Submit</button>
</form>
34 - Check Radio Buttons and Checkboxes by Default
在 input 新增 checked 屬性,就會默認被選中
<form action="/submit-cat-photo">
<label><input type="radio" name="indoor-outdoor" checked> Indoor</label>
<label><input type="radio" name="indoor-outdoor"> Outdoor</label>
<label><input type="checkbox" name="personality" checked> Loving</label>
<label><input type="checkbox" name="personality"> Lazy</label>
<label><input type="checkbox" name="personality"> Energetic</label>
<input type="text" placeholder="cat photo URL" required>
<button type="submit">Submit</button>
</form>
35 - Nest Many Elements within a Single Div Element
<div>
<p>Things cats love:</p>
<ul>
<li>cat nip</li>
<li>laser pointers</li>
<li>lasagna</li>
</ul>
<p>Top 3 things cats hate:</p>
<ol>
<li>flea treatment</li>
<li>thunder</li>
<li>other cats</li>
</ol>
</div>
36 - Give a Background Color to a Div Element
<style>
.silver-background {
background-color: silver;
}
</style>
<div class="silver-background">
<p >Things cats love:</p>
<ul>
<li>cat nip</li>
<li>laser pointers</li>
<li>lasagna</li>
</ul>
<p>Top 3 things cats hate:</p>
<ol>
<li>flea treatment</li>
<li>thunder</li>
<li>other cats</li>
</ol>
</div>
37 - Set the ID of an Element
38 - Use an ID Attribute to Style an Element
<style>
#cat-photo-form {
background-color: green;
}
</style>
<h2 id="cat-photo-form">
39 - Adjusting the Padding of an Element
<style>
.green-box {
background-color: green;
padding: 20px;
}
</style>
40 - Adjust the Margin of an Element
<style>
.injected-text {
margin-bottom: -25px;
text-align: center;
}
.box {
border-style: solid;
border-color: black;
border-width: 5px;
text-align: center;
}
.yellow-box {
background-color: yellow;
padding: 10px;
}
.red-box {
background-color: red;
padding: 20px;
margin: 20px;
}
.green-box {
background-color: green;
padding: 20px;
margin: 20px;
}
</style>
<h5 class="injected-text">margin</h5>
<div class="box yellow-box">
<h5 class="box red-box">padding</h5>
<h5 class="box green-box">padding</h5>
</div>
.injected-text { margin-bottom: -25px; text-align: center; }
.box { border-style: solid; border-color: black; border-width: 5px; text-align: center; }
.yellow-box { background-color: yellow; padding: 10px; }
.red-box { background-color: red; padding: 20px; margin: 20px; }
.green-box { background-color: green; padding: 20px; margin: 20px; } </style>
margin
padding
padding