JS工具函数助力高效开发

1.校验数据类型

export const typeOf = function (obj) {
  return Object.prototype.toString.call(obj).slice(8, -1).toLowerCase();
};

 

2.开启全屏

export const launchFullscreen = (element) => {
  if (element.requestFullscreen) {
    element.requestFullscreen();
  } else if (element.mozRequestFullScreen) {
    element.mozRequestFullScreen();
  } else if (element.msRequestFullscreen) {
    element.msRequestFullscreen();
  } else if (element.webkitRequestFullscreen) {
    element.webkitRequestFullScreen();
  }
};

 

3.关闭全屏

export const exitFullscreen = () => {
  if (document.exitFullscreen) {
    document.exitFullscreen();
  } else if (document.msExitFullscreen) {
    document.msExitFullscreen();
  } else if (document.mozCancelFullScreen) {
    document.mozCancelFullScreen();
  } else if (document.webkitExitFullscreen) {
    document.webkitExitFullscreen();
  }
};

 

4.大小写转换

export const turnCase = (str, type) => {
  switch (type) {
    case 1:
      return str.toUpperCase();
    case 2:
      return str.toLowerCase();
    case 3:
      //return str[0].toUpperCase() + str.substr(1).toLowerCase() // substr 已不推荐使用
      return str[0].toUpperCase() + str.substring(1).toLowerCase();
    default:
      return str;
  }
};

 

5.解析URL参数

export const getSearchParams = () => {
  const searchPar = new URLSearchParams(window.location.search);
  const paramsObj = {};
  for (const [key, value] of searchPar.entries()) {
    paramsObj[key] = value;
  }
  return paramsObj;
};

 

6.判断手机是Android还是IOS

/**
 * 1: ios
 * 2: android
 * 3: 其它
 */
export const getOSType = () => {
  let u = navigator.userAgent;
  let isAndroid = u.indexOf("Android") > -1 || u.indexOf("Linux") > -1;
  let isIOS = !!u.match(/\(i[^;]+;( U;)? CPU.+Mac OS X/);
  if (isIOS) {
    return 1;
  }
  if (isAndroid) {
    return 2;
  }
  return 3;
};

 

7.数组对象根据字段去重

export const uniqueArrayObject = (arr = [], key = "id") => {
  if (arr.length === 0) return;
  let list = [];
  const map = {};
  arr.forEach((item) => {
    if (!map[item[key]]) {
      map[item[key]] = item;
    }
  });
  list = Object.values(map);

  return list;
};

 

8.滚动到页面顶部

export const scrollToTop = () => {
  const height = document.documentElement.scrollTop || document.body.scrollTop;
  if (height > 0) {
    window.requestAnimationFrame(scrollToTop);
    window.scrollTo(0, height - height / 8);
  }
};

 

9.滚动到元素位置

export const smoothScroll = (element) => {
  document.querySelector(element).scrollIntoView({
    behavior: "smooth",
  });
};

 

10.金额格式化

参数：

{number} number：要格式化的数字

{number} decimals：保留几位小数

{string} dec_point：小数点符号

{string} thousands_sep：千分位符号

export const moneyFormat = (number, decimals, dec_point, thousands_sep) => {
  number = (number + "").replace(/[^0-9+-Ee.]/g, "");
  const n = !isFinite(+number) ? 0 : +number;
  const prec = !isFinite(+decimals) ? 2 : Math.abs(decimals);
  const sep = typeof thousands_sep === "undefined" ? "," : thousands_sep;
  const dec = typeof dec_point === "undefined" ? "." : dec_point;
  let s = "";
  const toFixedFix = function (n, prec) {
    const k = Math.pow(10, prec);
    return "" + Math.ceil(n * k) / k;
  };
  s = (prec ? toFixedFix(n, prec) : "" + Math.round(n)).split(".");
  const re = /(-?\d+)(\d{3})/;
  while (re.test(s[0])) {
    s[0] = s[0].replace(re, "$1" + sep + "$2");
  }

  if ((s[1] || "").length < prec) {
    s[1] = s[1] || "";
    s[1] += new Array(prec - s[1].length + 1).join("0");
  }
  return s.join(dec);
};

示例：

moneyFormat(10000000) // 10,000,000.00
moneyFormat(10000000, 3, '.', '-') // 10-000-000.000

 

11.存储操作

class MyCache {
  constructor(isLocal = true) {
    this.storage = isLocal ? localStorage : sessionStorage
  }

  setItem(key, value) {
    if (typeof (value) === 'object') value = JSON.stringify(value)
    this.storage.setItem(key, value)
  }

  getItem(key) {
    try {
      return JSON.parse(this.storage.getItem(key))
    } catch (err) {
      return this.storage.getItem(key)
    }
  }

  removeItem(key) {
    this.storage.removeItem(key)
  }

  clear() {
    this.storage.clear()
  }

  key(index) {
    return this.storage.key(index)
  }

  length() {
    return this.storage.length
  }
}

const localCache = new MyCache()
const sessionCache = new MyCache(false)

export { localCache, sessionCache }

其优点在于解决了对象存储的手动转换问题。

 

12.下载文件

参数：

api 接口

params 请求参数

fileName 文件名

const downloadFile = (api, params, fileName, type = 'get') => {
  axios({
    method: type,
    url: api,
    responseType: 'blob', 
    params: params
  }).then((res) => {
    let str = res.headers['content-disposition']
    if (!res || !str) {
      return
    }
    let suffix = ''
    // 截取文件名和文件类型
    if (str.lastIndexOf('.')) {
      fileName ? '' : fileName = decodeURI(str.substring(str.indexOf('=') + 1, str.lastIndexOf('.')))
      suffix = str.substring(str.lastIndexOf('.'), str.length)
    }
    //  如果支持微软的文件下载方式(ie10+浏览器)
    if (window.navigator.msSaveBlob) {
      try {
        const blobObject = new Blob([res.data]);
        window.navigator.msSaveBlob(blobObject, fileName + suffix);
      } catch (e) {
        console.log(e);
      }
    } else {
      //  其他浏览器
      let url = window.URL.createObjectURL(res.data)
      let link = document.createElement('a')
      link.style.display = 'none'
      link.href = url
      link.setAttribute('download', fileName + suffix)
      document.body.appendChild(link)
      link.click()
      document.body.removeChild(link)
      window.URL.revokeObjectURL(link.href);
    }
  }).catch((err) => {
    console.log(err.message);
  })
}

 

13.深拷贝

export const clone = (parent) => {
  // 判断类型
  const isType = (obj, type) => {
    if (typeof obj !== "object") return false;
    const typeString = Object.prototype.toString.call(obj);
    let flag;
    switch (type) {
      case "Array":
        flag = typeString === "[object Array]";
        break;
      case "Date":
        flag = typeString === "[object Date]";
        break;
      case "RegExp":
        flag = typeString === "[object RegExp]";
        break;
      default:
        flag = false;
    }
    return flag;
  };

  // 处理正则
  const getRegExp = (re) => {
    var flags = "";
    if (re.global) flags += "g";
    if (re.ignoreCase) flags += "i";
    if (re.multiline) flags += "m";
    return flags;
  };
  // 维护两个储存循环引用的数组
  const parents = [];
  const children = [];

  const _clone = (parent) => {
    if (parent === null) return null;
    if (typeof parent !== "object") return parent;

    let child, proto;

    if (isType(parent, "Array")) {
      // 对数组做特殊处理
      child = [];
    } else if (isType(parent, "RegExp")) {
      // 对正则对象做特殊处理
      child = new RegExp(parent.source, getRegExp(parent));
      if (parent.lastIndex) child.lastIndex = parent.lastIndex;
    } else if (isType(parent, "Date")) {
      // 对Date对象做特殊处理
      child = new Date(parent.getTime());
    } else {
      // 处理对象原型
      proto = Object.getPrototypeOf(parent);
      // 利用Object.create切断原型链
      child = Object.create(proto);
    }

    // 处理循环引用
    const index = parents.indexOf(parent);

    if (index != -1) {
      // 如果父数组存在本对象,说明之前已经被引用过,直接返回此对象
      return children[index];
    }
    parents.push(parent);
    children.push(child);

    for (let i in parent) {
      // 递归
      child[i] = _clone(parent[i]);
    }

    return child;
  };
  return _clone(parent);
};

此方法存在一定局限性：一些特殊情况没有处理：例如Buffer对象、Promise、Set、Map。

如果确实想要完备的深拷贝，推荐使用 lodash 中的 cloneDeep 方法。

 

14.模糊搜索

参数：

list 原数组

keyWord 查询的关键词

attribute 数组需要检索属性

export const fuzzyQuery = (list, keyWord, attribute = "name") => {
  const reg = new RegExp(keyWord);
  const arr = [];
  for (let i = 0; i < list.length; i++) {
    if (reg.test(list[i][attribute])) {
      arr.push(list[i]);
    }
  }
  return arr;
};

 

15.遍历树节点

export const foreachTree = (data, callback, childrenName = "children") => {
  for (let i = 0; i < data.length; i++) {
    callback(data[i]);
    if (data[i][childrenName] && data[i][childrenName].length > 0) {
      foreachTree(data[i][childrenName], callback, childrenName);
    }
  }
};

使用示例

const treeData = [
  {
    id: 1,
    label: "一级 1",
    children: [
      {
        id: 4,
        label: "二级 1-1",
        children: [
          {
            id: 9,
            label: "三级 1-1-1",
          },
          {
            id: 10,
            label: "三级 1-1-2",
          },
        ],
      },
    ],
  },
  {
    id: 2,
    label: "一级 2",
    children: [
      {
        id: 5,
        label: "二级 2-1",
      },
      {
        id: 6,
        label: "二级 2-2",
      },
    ],
  },
  {
    id: 3,
    label: "一级 3",
    children: [
      {
        id: 7,
        label: "二级 3-1",
      },
      {
        id: 8,
        label: "二级 3-2",
      },
    ],
  },
];

let result;
foreachTree(data, (item) => {
  if (item.id === 9) {
    result = item;
  }
});
console.log("result", result); // {id: 9,label: "三级 1-1-1"}