js 高频实用函数封装汇总（持续更新）

// 字符串获取指定字符的所有下标
export function getIndexList(string, char) {
  let arr = [];
  let index = -1;
  do {
    index = string.indexOf(char, index + 1);
    if (index != -1) {
      arr.push(index);
    }
  } while (index != -1);
  if (arr.length > 0) {
    return arr;
  } else {
    return -1;
  }
}

let str = "012$456$8";
let indexList = getIndexList(str, "$");
console.log(indexList); // [ 3, 7 ]

//字符串统计指定字符出现的次数
export function count(string, char) {
  let array = string.match(new RegExp(char, "g"));
  return array ? array.length : 0;
}

let str = "012$456$8";

// 特殊字符需用 \\ 转义
let num = count(str, "\\$");
console.log(num); //2

str = "a23a23a23a";
num = count(str, "a");
console.log(num); //4

// 对象数组移除指定对象  removeObjItem(objList, "age", 20);
export function removeObjItem(arr, prop, value) {
  let targetIndex = arr.findIndex((itemTemp) => itemTemp[prop] === value);
  if (targetIndex !== -1) {
    arr.splice(targetIndex, 1);
  }
}

// 对象数组指定对象置顶  topObjItem(objList, "age", 20);
export function topObjItem(arr, prop, value) {
  let targetIndex = arr.findIndex((itemTemp) => itemTemp[prop] === value);
  if (targetIndex !== -1) {
    let item = arr[targetIndex]
    arr.splice(targetIndex, 1);
    arr.unshift(item)
  }
}

// 对象数组获取指定对象下标
export function getObjArrIndex(arr, prop, value) {
  let targetIndex = arr.findIndex((itemTemp) => itemTemp[prop] === value);
  if (targetIndex !== -1) {
    return targetIndex
  }
}

// 对象数组按指定属性排序 arr5.sort(sortBy('id',1))   attr：根据该属性排序；rev：升序1或降序-1，不填则默认为1
export function sortBy(attr, rev) {
  if (rev == undefined) {
    rev = 1
  } else {
    (rev) ? 1: -1;
  }
  return function (a, b) {
    a = a[attr];
    b = b[attr];
    if (a < b) {
      return rev * -1
    }
    if (a > b) {
      return rev * 1
    }
    return 0;
  }
}

 //日期转字符串 2023-02-01
 export function DateToStr(date) {
   if (typeof date === 'string') {
     return date
   }
   let year = date.getFullYear(); //年
   let month = date.getMonth(); //月
   let day = date.getDate(); //日
   return year + "-" +
     ((month + 1) > 9 ? (month + 1) : "0" + (month + 1)) + "-" +
     (day > 9 ? day : ("0" + day)) + " "
 }

//日期+时间 转字符串  2023-02-01 17:40:35
 export function DateTimeToStr(DateTime) {
   if (typeof DateTime === 'string') {
     return DateTime
   }
   var year = DateTime.getFullYear(); //年
   var month = DateTime.getMonth(); //月
   var day = DateTime.getDate(); //日
   var hours = DateTime.getHours(); //时
   var min = DateTime.getMinutes(); //分
   var second = DateTime.getSeconds(); //秒
   return year + "-" +
     ((month + 1) > 9 ? (month + 1) : "0" + (month + 1)) + "-" +
     (day > 9 ? day : ("0" + day)) + " " +
     (hours > 9 ? hours : ("0" + hours)) + ":" +
     (min > 9 ? min : ("0" + min)) + ":" +
     (second > 9 ? second : ("0" + second));
 }

// 生成随机id
export function randomID() {
  return (Math.random() + new Date().getTime()).toString(32).slice(0, 8)
}