feat: add some string funcs

src/string/index.ts

@@ -0,0 +1,114 @@
+import { getRandomNum } from '../number'
+
+const randomLetters = [
+  '0', '1', '2', '3', '4', '5',
+  '6', '7', '8', '9', 'A', 'B',
+  'C', 'D', 'E', 'F', 'G', 'H',
+  'I', 'J', 'K', 'L', 'M', 'N',
+  'O', 'P', 'Q', 'R', 'S', 'T',
+  'U', 'V', 'W', 'X', 'Y', 'Z'
+]
+
+/**
+ * Capitalize the first letter of the English string
+ *
+ * @param {string} str
+ * @returns {string}
+ *
+ * example: capitalize('hello world!') => 'Hello world!'
+ */
+export const capitalizeStr = (str: string): string => str.charAt(0).toUpperCase() + str.slice(1)
+
+/**
+ * Flip the string
+ *
+ * @param {string} str
+ * @returns {string}
+ *
+ * example: reverseStr('hello world!') => '!dlrow olleh'
+ */
+export const reverseStr = (str: string): string => str.split('').reverse().join('')
+
+/**
+ * Generate a random string with `numbers` and `uppercase letters`
+ *
+ * @param randomStrLen random string length
+ * @returns {string}
+ *
+ * example: getRandomStr() => '6HG8ASDHLF'
+ */
+export const getRandomStr = (randomStrLen = 10): string => {
+  /**
+   * another way:
+   * Math.random().toString(36).slice(2)
+   *
+   * 固定长度为 11 位的随机字符串（数字 + 小写字母）
+   */
+  const len = randomLetters.length
+  let res = ''
+  for (let i = 0; i < randomStrLen; i++) {
+    res += randomLetters[getRandomNum(0, len)]
+  }
+  return res
+}
+
+/**
+ * Truncate a string of specified length
+ * 截断指定长度的字符串，剩余字符省略号表示
+ *
+ * @param str
+ * @param len
+ * @returns
+ *
+ * example: truncateStr('Truncate a string of specified length', 17) => 'Truncate a str...'
+ */
+export const truncateStr = (str: string, len?: number) => {
+  if (len === undefined) {
+    return str
+  }
+  return str.length < len ? str : `${str.slice(0, len - 3)}...`
+}
+
+/**
+ * Strip HTML elements from a string
+ * 去除字符串中的 HTML 元素
+ *
+ * @param htmlStr
+ * @returns
+ */
+export const stripHtmlEl = (htmlStr: string) => (new DOMParser().parseFromString(htmlStr, 'text/html')).body.textContent || ''
+
+/**
+ * Convert `RGB` to `Hex`
+ * 将 rgb 颜色值转换为 16 进制颜色值
+ *
+ * @param r
+ * @param g
+ * @param b
+ * @returns
+ *
+ * example: convertRgbToHex(255, 255, 255) => '#ffffff'
+ */
+export const convertRgbToHex = (
+  r: number,
+  g: number,
+  b: number
+) => {
+  if (
+    r < 0 || r > 255
+    || g < 0 || g > 255
+    || b < 0 || b > 255
+  ) {
+    throw new Error('s')
+  }
+  return `#${((1 << 24) + (r << 16) + (g << 8) + b).toString(16).slice(1)}`
+}
+
+/**
+ * Get a random hexadecimal color value
+ * 获取随机的 16 进制颜色值
+ * [`.padEnd()`](https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/String/padEnd)
+ * 不足的位数用 0 填充（目标长度为 6）
+ * @returns
+ */
+export const getRandomHex = () => `#${(~~(Math.random() * 0xFFFFFF)).toString(16).padEnd(6, '0')}`