# FrontEnd
## CSS选择器
### 类型
| 选择器类型 | 用法 | 说明 |
| ---------------------------------------------------------------------------- | ------------ | -------------------------- |
| ID选择器 | #myid | 选择`id='myid'`的标签 |
| 类选择器 | .myclassname | 选择`class='myclassname'`的标签 |
| 标签选择器 | div,h1,p | 选择`div`、`h1`以及`p`标签 |
| 相邻选择器 | h1+p | 选择紧跟在`h1`标签同级的`p`标签 |
| 子选择器 | ul > li | 选择`ul`标签的子标签中的`li`标签 |
| 后代选择器 | li a | 选择`li`标签的子孙标签中的`a`标签 |
| 通配符选择器 | \* | 选择所有标签，也可以用来选择某元素的所有子标签 |
| 属性选择器 | a\[title] | 选择`a`标签中，有`title`属性的标签 |
| 伪类选择器[(参考)](https://developer.mozilla.org/zh-CN/docs/Web/CSS/Pseudo-classes) | button:hover | 选择鼠标悬停的`button`标签 |
CSS对于ID选择器、类选择器、标签选择器的优先级分别为100、10、1
选择器越特殊，优先级越高。所以如下直接写在标签里的CSS优先级最高：
```html
hello css
```
但是应遵循样式和内容分离的原则，不应将样式写在标签内。
###
### 示例
```css
```
```html
*
.container *
#head
.preference
ul
- ul>li
- ul li:nth-of-type(2)
- ul li:nth-last-child(1)
ul+span
ul~a
a[href^='https']
```
## CodeShow
### 点击复制
```js
copy_info() {
let oInput = document.createElement('input')
oInput.value = `id: ${this.id}, name: "${this.name}"`
document.body.appendChild(oInput)
oInput.select()
document.execCommand('Copy')
this.$message('复制成功！')
},
```
## JS日期
```js
new Date().toISOString() // => "2021-06-11T07:20:06.642Z"
new Date().toISOString().slice(0,10) // => "2021-06-11"
```
## Postman
手动设置`Authorization`认证`token`
```js
// set request params
const postRequest = {
url: 'http://localhost:5450/oauth/token.json?', //请求token的接口
method: 'POST',
header: {
'Content-Type': 'application/json'
},
body: {
mode: 'raw',
raw: JSON.stringify({
client_id:"2642d4c1ebed62755b352d2b6a42c9096372450370b387c56f158423e6612552",
client_secret:"17ec1e2ead9b396da8463723b979664d8b2d8d0e7712fafcc97f154c7f0b5d41",
grant_type:"client_credentials",
scope: ""
})
}
};
pm.sendRequest(postRequest, (error, response) => {
error ? console.log(error) : setUserSessionKey(response)
});
// set user_session_key
function setUserSessionKey(response){
var result = response.json()
pm.request.headers.add({
key:"Authorization",
value: "Bearer "+result.access_token
})
}
```
---
# Agent Instructions: Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.
Perform an HTTP GET request on the current page URL with the `ask` query parameter:
```
GET https://dokiy.gitbook.io/note/other/frontend.md?ask=
```
The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.
Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.