关于前端:js-必备工具代码段建议收藏持续更新ing

一、数组解决

1. 数组去重

1. 纯数组去重(6 种办法)

class ArrayToHeavy {
      // new Set 去重
      newSetHeavy(arr) {return Array.from(new Set(arr))
      }

      // .indexOf 或 lastIndexOf 去重
      indexHeavy(arr) {let newArr = [];
        arr.forEach((val, index) => {newArr.indexOf(val) === -1 ? newArr.push(val) : '';
        });
        return newArr
      }

      // 通过 filter 过滤返回一个新数组在原数组中比照用 indexof 去重
      filterHeavy(arr) {return arr.filter((item, index, self) => {return self.indexOf(item) === index; // 比拟数组中每一项是否为其（indexof）首次查找的索引值(index)
        })
      }

      // 通过 splice 扭转原数组去重
      spliceHeavy(arr) {
        let len = arr.length;
        for (let i = 0; i < len; i++) {for (let j = i + 1; j < len; j++) {if (arr[i] == arr[j]) {arr.splice(j, 1);
              len--;
              j--
            }
          }
        }
      }

      /* 相邻元素去重
       这种办法首先调用了数组的排序办法 sort()，而后依据排序后的后果进行遍历及相邻元素比对，如果相等则跳过改元素，直到遍历完结 */
      uniqueHeavy(arr) {if (!Array.isArray(arr)) {console.log('type error!')
          return
        }
        arr = arr.sort()
        let res = []
        for (let i = 0; i < arr.length; i++) {if (arr[i] !== arr[i - 1]) {res.push(arr[i])
          }
        }
        return res
      }

      /* 利用对象属性去重
        创立空对象，遍历数组，将数组中的值设为对象的属性，并给该属性赋初始值 1，每呈现一次，对应的属性值减少 1，这样，属性值对应的就是该元素呈现的次数了 */
     ObjHeavy(arr) {if (!Array.isArray(arr)) {console.log('type error!')
        return
      }
      let res = [],
        obj = {}
      for (let i = 0; i < arr.length; i++) {if (!obj[arr[i]]) {res.push(arr[i])
          obj[arr[i]] = 1
        } else {obj[arr[i]]++
        }
      }
      return res
    }
    }
    const ArrayToHeavy_handle = new ArrayToHeavy()
    console.log(ArrayToHeavy_handle.newSetHeavy([1, 1])) // [1]

2. 对象数组去重

1. 去重雷同 id 的对象

let person = [{ id: 0, name: "A"},
{id: 0, name: "b"}
];

let obj = {};
let peon = person.reduce((cur, next) => {obj[next.id] ? "" : (obj[next.id] = true && cur.push(next));
  return cur;
}, []); // 设置 cur 默认类型为数组，并且初始值为空的数组
peon // [{id: 0, name: "A"}]

2. 数组排序 10 种实用办法

{1} 冒泡排序

• 解释：冒泡排序算法就是顺次比拟大小，小的的大的进行地位上的替换。
• 实现原理：
  当 i = 0 的时候，外面的循环残缺执行，从 j = 0 执行到 j =6, 这也就是第一遍排序，后果是将最大的数排到了最初，这一遍循环完结后的后果应该是[8,34,21,53,12,95

当 i = 1 的时候，外面的循环再次残缺执行，因为最大的数曾经在最初了，没有必要去比拟数组的最初两项，这也是 j <arr.length-1- i 的奇妙之处，后果是 [8,34,21,12,53,95]
说到这里，法则就分明了，每次将剩下数组外面最大的一个数排到最初面，当第一个循环执行到最初的时候，也就是 i =6, 此时，j=0, 只须要比拟数组的第一和第二项，比拟结束，返回。

let arr=[8,95,34,21,53,12];
 function sortarr(arr){for(i=0;i<arr.length-1;i++){for(j=0;j<arr.length-1-i;j++){if(arr[j]>arr[j+1]){var temp=arr[j];
     arr[j]=arr[j+1];
     arr[j+1]=temp;
    }
   }
  }
  return arr;
 }
 sortarr(arr); // [8,12,21,34,53,95]

(2) 抉择排序

• 解释：顺次找到残余元素最小值，搁置排好序的开端（第一个放在结尾）
  在工夫复杂度上体现最稳固的排序算法之一，因为无论什么数据进去都是 O(n²)的工夫复杂度，所以用到它的时候，数据规模越小越好。惟一的益处可能就是不占用额定的内存空间

  function selectionSort(arr) {
  var len = arr.length;
  var minIndex, temp;
  for (var i = 0; i < len - 1; i++) {
      minIndex = i;
      for (var j = i + 1; j < len; j++) {if (arr[j] < arr[minIndex]) {     // 寻找最小的数
              minIndex = j;                 // 将最小数的索引保留
          }
      }
      temp = arr[i];
      arr[i] = arr[minIndex];
      arr[minIndex] = temp;
  }
  return arr;
  }

  3. 数组拷贝

  (1) [].concat.apply([], 被拷贝的数组) 适宜解决一维数组

let a = [1,2];
let b = [].concat.apply([], a);
b[0] = 0;
a // => [1, 2]
b // => [0, 2]

4. 解决二维数组

(1) 将间断的二维数组中的对应索引项合并为一个数组，返回合并后的二维数组

输出：var data = [[2001, 10, 20],
[2002, 30 ,40],
[2003, 50 ,60]
]
输入：[[2001, 2002, 2003],
[10, 30, 50],
[20, 40, 60]
]

实现：var getBarData = [];
    data[0].map(item => {getBarData.push([])
    });
    data.forEach((item, inx) => {for(var i = 0; i < data[0].length; i++) {getBarData[i].push(item[i])
      }
    })

5. 按 指定条件 查找数组中的元素

(1) 查找数组最大值

 输出:   let a = [1,2,3,4]
 输入：4

1. 利用 Math 办法通过 apply 将数组元素一个一个拆分开来，而后在传递到 Math.max()办法中
Math.max.apply(null, a)

2. Math.max(...a)

3. 利用 sort 办法
    let resultArr = a.sort(function(a, b) {return b - a;});
     resultArr[0] // 5

6. 按指定条件过滤数组

(1) 过滤数组中值为 false 的值

输出：let a = [0,0,false,null,3]
输入：[3]

let b = a.filter(Boolean) // [3]

7. 类数组转为数组

(1) [].slice.call(obj) 或Array.prototype.slice.call(obj) 或 Array.prototype.concat.apply([],obj)

[].slice.call({length:2,0:1,1:2}) // [1 ,2]
Array.prototype.concat.apply([],{length:1,0:1}) // [1]

(2) Array.from(cArr) 或 […obj]

Array.from({length:1,0:1}) // [1]

8. 扁平化数组

输出: var arr = [[[1,2,3],[[4,5,6]]]]
输入: [1,2,3,4,5,6]

(1) reduce 递归法

 var flatten = (arr) => {return arr.reduce((pre, next) => {return pre.concat(Array.isArray(next) ? flatten(next) : next);
          }, [])
         }
        flatten(arr) // [1,2,3,4,5,6]

二、对象解决

1. 将对象转为数组

• 利用 Object.keys()

  const obj = {
       "sex_wxx": "性别",
       "income_wxx": "支出",
       "age_wxx": "年龄"
   };
   let arr = [];
   Object.keys(obj).forEach(v => {let o = {};
       o[v] = obj[v];
       arr.push(o)
   })
  console.log(arr) // [{sex_wxx: '性别'}, {income_wxx: '支出'},{age_wxx: '年龄'}]

• 利用 Object.entries()

Object.entries(obj).forEach(item => {let o = {}
o[item[0]] = item[1]
arr.push(o)
})

• Object.keys()和 map()联合

Object.keys(obj).map(v => { return v = {[v]: obj[v]} })

2. 递归对象获取 value

var obj = {a:{w:1,y:2,x:3},
b:{s:4,j:5,x:6},
c:{car:7,cat:8,mao:9}
}
function f(s){for(var i in s){if(typeof s[i]=="object"){f(s[i])
}else{console.log(s[i]);
  }
}
}
f(obj) // 1,2,3,4,5,6,7,8,9

3. 判断两个对象是否相等

Object.entries({name:1}).toString() === Object.entries({name:1}).toString() // true

4. 从一个对象条件匹配另一个对象

用过滤（filter）判断（every）每一项是否符合条件

let obj = {name:  'ops'}
let arr = [{name: 'q'}, {name: 'ops', kl: 'oop'}]
var _key= Object.keys(obj)

arr.filter(item=>_key.every(k=>obj[k]===item[k])) // {name: 'ops', kl: 'oop'}

5. 对象转为 url 参数拼接

输出：

{
a:1,
b:2
}

输入：

a=1&b=2

function obj2strUrl (obj) {
    let str="";
    for (let key in obj) {str = `${str}${key}=${obj[key]}&`
    };
    str = str.substring(0, str.length-1);
    return str;
}

反转：拼接的 url 参数转为对象

/**
 * @param {string} url
 * @returns {Object}
 */
function param2Obj(url) {const search = decodeURIComponent(url.split('?')[1]).replace(/\+/g, ' ')
  if (!search) {return {}
  }
  const obj = {}
  const searchArr = search.split('&')
  searchArr.forEach(v => {const index = v.indexOf('=')
    if (index !== -1) {const name = v.substring(0, index)
      const val = v.substring(index + 1, v.length)
      obj[name] = val
    }
  })
  return obj
}

三、字符串解决

1. 将被 字符串包裹的对象 转为 js 对象

输出 ‘{name: qwer, id: 1, ops: poi}’,=> 输入 {name: ‘qwer’, id: ‘1’, ops: ‘poi’}

function strToObj(str) {let arr = str.replace(/{|}|\s*/g, '').split(','),
        obj = {}
    arr.forEach(val => {let i = val.indexOf(':')
        obj[val.substr(0, i)] = val.substr(i + 1);
});
return obj
}
console.log(strToObj('{name: qwer, id: 1, ops: poi}')) => {name: 'qwer', id: '1', ops: 'poi'}

2. 格式化 string/number 类型的日期

let date = '20220408000009';
function f(str, type) {
let i = 0,_type = type || 'xxxx-xx-xx xx:xx:xx'
return _type.replace(/x/g, () => str[i++])
}
f(date)

3. 计算 字符串宽度（px）

// 1. 准确计算
function computedTextWidth (text) {var canvas = document.createElement('canvas');
     canvas.id = 'computedTextWidth';
     canvas.style.cssText = 'visibility:hidden;position: absolute;left: -999em;top:-999em;';
     document.body.appendChild(canvas);
    var context = canvas.getContext('2d');
    context.font = '12px';
    context.fillText(text, 0, 0);
    return context.measureText(text).width;
}
computedTextWidth('33333333') // 100

// 2. 误差计算(差值为 1 /4)
computedTextWidth(text, fontSize = 14) {let span = document.getElementById('computedTextWidth');
  if (!span) {span = document.createElement('span');
    span.id = 'computedTextWidth';
    span.style.cssText = 'visibility:hidden;position: absolute;left: -999em;top:-999em;';
    document.body.appendChild(span);
  }
  span.style.fontSize = `${fontSize}px`;
  span.innerHTML = text;
  return span.offsetWidth;
};

4. 提取字符串中的 数字

(1) match 办法

var str = '123AAAA098'
var numArr = str.match(/\d+/g)
    numArr // => ["123", "098"]

(2) replace 办法

var s ="4500 元，6,700";
var num= s.replace(/[^0-9]/ig,"");
num // 45006700

5. 提取字符串中的指定值 ( 度量值)

let str = '申请量 3 件，总量 3,541，98234，4.5，90%，4.5% 件。';
str.match(/\d+(.\d+\%)|\d+(,\d+)|\d+(\.\d+)|\d+\%|\d+/img);
str // ['3', '3,541', '98234', '4.5', '90%', '4.5%']

四、日期工夫类

1. 依据开始工夫 + 日 / 月 / 年数 计算截止日期

(1) 开始日期 + 天数 = 截止日期

export function getEndDay(dateTemp, days) {dateTemp = dateTemp.split("-")
  var nDate = new Date(dateTemp[1] + "-" + dateTemp[2] + "-" + dateTemp[0]) // 格式化工夫
  var millSeconds = Math.abs(nDate) + days * 24 * 60 * 60 * 1000
  var rDate = new Date(millSeconds)
  var year = rDate.getFullYear()
  var month = rDate.getMonth() + 1
  if (month < 10) month = "0" + month
  var date = rDate.getDate()
  if (date < 10) date = "0" + date
  return year + "-" + month + "-" + date
}
应用：getEndDay('年 - 月 - 日', '天数')
例：getEndDay('2021-11-11', '1')  =>  '2021-11-12'

(2) 开始日期 + 月数 = 截止日期

 export function getEndMonth(dtstr, n) {var s = dtstr.split("-")
     var yy = parseInt(s[0])
     var mm = parseInt(s[1])
     var dd = parseInt(s[2])
     var dt = new Date(yy, mm, dd)
     
     var num=dt.getMonth() + parseInt(n)
     if(num/12>1){yy+=Math.floor(num/12)
        mm=num%12
     }else{mm+=parseInt(n)
     }
     return yy + "-" + mm  + "-" + dd
 }
 应用：getEndMonth('年 - 月 - 日', '月数')
 例：getEndMonth('2021-11-11', '1')  =>  '2021-12-11'

(3)开始日期 + 年数 = 截止日期

export function getEndYear(date, years) {var now = new Date(date);
  var intYear = now.getFullYear() + parseInt(years);
  var intMonth = now.getMonth() + 1; // 失常的月份，var intDay = now.getDate() - 1; // 日期 -1
  if (intDay == 0) {
  intMonth--; // 缩小一个月
  if (intMonth == 0) {
  intYear--; //0: 缩小一年
  intMonth = 12;
  intDay = 31;
  }
  else if (intMonth == 4 || intMonth == 6 || intMonth == 9 || intMonth == 11) {intDay = 30; //4,6,9,11:30 天}
  else if (intMonth == 2) {
  intDay = 28; //2:28/29
  if (intYear % 4 == 0) {intDay = 29;}
  } else {intDay = 31; //1,3,5,7,8,10,12 :31 天}
  }

  var strMonth = (intMonth) < 10 ? "0" + (intMonth).toString() : (intMonth).toString();
  var strDay = (intDay) < 10 ? "0" + (intDay).toString() : (intDay).toString();
  var strEndDate = intYear + "-" + strMonth + "-" + strDay;
  return strEndDate;
  }
  应用：getEndYear('年 - 月 - 日', '月数') 
  例：getEndYear('2021-11-11', '1') => '2022-12-11'

2. 获取指定日期工夫

export function timeStremHandle() {let now = new Date() // 以后日期
  let nowDayOfWeek = now.getDay() // 明天本周的第几天
  let nowDay = now.getDate() // 以后日
  let nowMonth = now.getMonth() // 以后月
  let nowYear = now.getYear() // 以后年
  nowYear += (nowYear < 2000) ? 1900 : 0

  let lastMonthDate = new Date() // 上月日期
  lastMonthDate.setDate(1)
  lastMonthDate.setMonth(lastMonthDate.getMonth() - 1)
  let lastYear = lastMonthDate.getYear()
  let lastMonth = lastMonthDate.getMonth()

  return {
// 格式化日期：yyyy-MM-dd
    formatDate(date) {var myyear = date.getFullYear()
      var mymonth = date.getMonth() + 1
      var myweekday = date.getDate()

      if (mymonth < 10) {mymonth = "0" + mymonth}
      if (myweekday < 10) {myweekday = "0" + myweekday}
      return (myyear + "-" + mymonth + "-" + myweekday)
    },
    
    // 获取间断数字年月日
    getNumDate(){function formatNumber(n) {n = n.toString()
       return n[1] ? n : '0' + n
        }
      function formatDay (date) {var year = date.getFullYear()
       var month = date.getMonth() + 1
       var day = date.getDate()
       return [year, month, day].map(formatNumber).join('') +'' 
    }
        
     调用：formatDay(new Date()) // '20220923'
    },

// 取得某月的天数
    getMonthDays(myMonth) {var monthStartDate = new Date(nowYear, myMonth, 1)
      var monthEndDate = new Date(nowYear, myMonth + 1, 1)
      var days = (monthEndDate - monthStartDate) / (1000 * 60 * 60 * 24)
      return days
    },

// 取得本季度的开始月份
    getQuarterStartMonth() {
      var quarterStartMonth = 0
      if (nowMonth < 3) {quarterStartMonth = 0}
      if (2 < nowMonth && nowMonth < 6) {quarterStartMonth = 3}
      if (5 < nowMonth && nowMonth < 9) {quarterStartMonth = 6}
      if (nowMonth > 8) {quarterStartMonth = 9}
      return quarterStartMonth
    },

// 取得本周的开始日期
    getWeekStartDate() {var weekStartDate = new Date(nowYear, nowMonth, nowDay - nowDayOfWeek)
      return formatDate(weekStartDate)
    },

// 取得本周的进行日期
    getWeekEndDate() {var weekEndDate = new Date(nowYear, nowMonth, nowDay + (6 - nowDayOfWeek))
      return formatDate(weekEndDate)
    },

// 取得本月的开始日期
    getMonthStartDate() {var monthStartDate = new Date(nowYear, nowMonth, 1)
      return formatDate(monthStartDate)
    },

// 取得本月的进行日期
    getMonthEndDate() {var monthEndDate = new Date(nowYear, nowMonth, getMonthDays(nowMonth))
      return formatDate(monthEndDate)
    },

// 取得上月开始日期
    getLastMonthStartDate() {var lastMonthStartDate = new Date(nowYear, lastMonth, 1)
      return formatDate(lastMonthStartDate)
    },

// 取得上月进行日期
    getLastMonthEndDate() {var lastMonthEndDate = new Date(nowYear, lastMonth, getMonthDays(lastMonth))
      return formatDate(lastMonthEndDate)
    },

// 取得本季度的开始日期
    getQuarterStartDate() {var quarterStartDate = new Date(nowYear, getQuarterStartMonth(), 1)
      return formatDate(quarterStartDate)
    },

// 取得本季度的截止日期
    getQuarterEndDate() {var quarterEndMonth = getQuarterStartMonth() + 2
      var quarterStartDate = new Date(nowYear, quarterEndMonth, getMonthDays(quarterEndMonth))
      return formatDate(quarterStartDate)
    },
    
// 日期减
    DateDiff(sDate1, sDate2) {
      var aDate, oDate1, oDate2, iDays
      aDate = sDate1.split("-")
      oDate1 = new Date(aDate[0], aDate[1] - 1, aDate[2])
      aDate = sDate2.split("-")
      oDate2 = new Date(aDate[0], aDate[1] - 1, aDate[2])
      iDays = parseInt(Math.abs(oDate1 - oDate2) / 1000 / 60 / 60 / 24)
      if ((oDate1 - oDate2) < 0) {return -iDays}
      return iDays
    },

// 最近一个月年月日
 latelyTimeStrem() {var strem = new Date(now)
  strem.setDate(now.getDate() - 30)
  return {startDay: this.formatDate(new Date(nowYear, nowMonth, nowDay -30)),
    nowDay: this.formatDate(new Date(nowYear, nowMonth, nowDay))
  }
 }
  }
}

3. 获取以后工夫戳

export function getTime(type) {if (type === 'start') {return new Date().getTime() - 3600 * 1000 * 24 * 90} else {return new Date(new Date().toDateString())
    }
  }

4. 将工夫戳转为 {y}-{m}-{d} {h}:{i}:{s}

/**
 * @param {(Object|string|number)} time
 * @param {string} cFormat
 * @returns {string | null}
 * @description 工夫戳转为年月日时分秒
 * @example parseTime(1656577144101)  2022-06-30 16:19:04; 
 *          获取星期几:parseTime(1656577144101, '{y}-{m}-{d} {h}:{i}:{s}{a}'); 2022-06-30 16:19:04 四
 */
export function parseTime(time, cFormat) {if (arguments.length === 0 || !time) {return null}
  const format = cFormat || '{y}-{m}-{d} {h}:{i}:{s}'
  let date
  if (typeof time === 'object') {date = time} else {if ((typeof time === 'string')) {if ((/^[0-9]+$/.test(time))) {time = parseInt(time)
      } else {
        // https://stackoverflow.com/questions/4310953/invalid-date-in-safari
        time = time.replace(new RegExp(/-/gm), '/')
      }
    }

    if ((typeof time === 'number') && (time.toString().length === 10)) {time = time * 1000}
    date = new Date(time)
  }
  const formatObj = {y: date.getFullYear(),
    m: date.getMonth() + 1,
    d: date.getDate(),
    h: date.getHours(),
    i: date.getMinutes(),
    s: date.getSeconds(),
    a: date.getDay()}
  const time_str = format.replace(/{([ymdhisa])+}/g, (result, key) => {const value = formatObj[key]
    // Note: getDay() returns 0 on Sunday
    if (key === 'a') {return ['日', '一', '二', '三', '四', '五', '六'][value] }
    return value.toString().padStart(2, '0')
  })
  return time_str
}

5. 获取零碎时分秒

  export function getSystemTime() {
    let timer = null
    setInterval(function () {let time = new Date()
      let hour = checkTime(time.getHours())
      let minite = checkTime(time.getMinutes())
      let second = checkTime(time.getSeconds())
      function checkTime(i) {if (i < 10) return "0" + i
        return i
      }
      timer = hour + ":" + minite + ":" + second
      return timer
    }, 1000)
  }

6. 计算两个日期之间的距离

const dayDif = (date1, date2) =>
Math.ceil(Math.abs(date1.getTime() - date2.getTime()) / 86400000)
dayDif(new Date("2022-11-3"), new Date("2022-2-1"))  // 275

7. 查找日期位于一年中的第几天

const dayOfYear = (date) => Math.floor((date - new 
Date(date.getFullYear(), 0, 0)) / 1000 / 60 / 60 / 24);
dayOfYear(new Date());   // 311

五、屏蔽浏览器控制台

1. 写一个回调函数，让页面进行死循环

!function(){var _0x1cbb = ["tor", "struc", "call", "ger", "con", "bug", "de", "apply"];
        setInterval(check, 2e3);
        function check() {function doCheck(_0x1834ff) {if ((''+ _0x1834ff / _0x1834ff)['length'] !== 0x1 || _0x1834ff % 0x14 === 0x0) {(function() {return !![]}[_0x1cbb[0x4] + _0x1cbb[0x1] + _0x1cbb[0x0]
                    ](_0x1cbb[0x6] + _0x1cbb[0x5] + _0x1cbb[0x3]
                    )[_0x1cbb[0x2]]());
                } else {(function() {return ![]}[_0x1cbb[0x4] + _0x1cbb[0x1] + _0x1cbb[0x0]
                    ](_0x1cbb[0x6] + _0x1cbb[0x5] + _0x1cbb[0x3]
                    )[_0x1cbb[0x7]]());
                }
                doCheck(++_0x1834ff);
            }
            try {doCheck(0)
            } catch(err) {}};
      }();

六、加密算法

SHA 加密

解释：SHA- 1 是一种数据加密算法，该算法的思维是接管一段明文，而后以一种不可逆的形式将它转换成一段（通常更小）密文，也能够简略的了解为取一串输入码（称为预映射或信息），并把它们转化为长度较短、位数固定的输入序列即散列值（也称为信息摘要或信息认证代码）的过程。

function encodeUTF8 (s) {var i, r = [], c, x
        for (i = 0; i < s.length; i++)
        if ((c = s.charCodeAt(i)) < 0x80) r.push(c)
        else if (c < 0x800) r.push(0xC0 + (c >> 6 & 0x1F), 0x80 + (c & 0x3F))
        else {if ((x = c ^ 0xD800) >> 10 == 0) // 对四字节 UTF-16 转换为 Unicode
            c = (x << 10) + (s.charCodeAt(++i) ^ 0xDC00) + 0x10000,
                r.push(0xF0 + (c >> 18 & 0x7), 0x80 + (c >> 12 & 0x3F))
            else r.push(0xE0 + (c >> 12 & 0xF))
            r.push(0x80 + (c >> 6 & 0x3F), 0x80 + (c & 0x3F))
        }
        return r
    }
function sha (s) { // sh1 编码
          var data = new Uint8Array(encodeUTF8(s))
          var i, j, t
          var l = ((data.length + 8) >>> 6 << 4) + 16, s = new Uint8Array(l << 2)
          s.set(new Uint8Array(data.buffer)), s = new Uint32Array(s.buffer)
          for (t = new DataView(s.buffer), i = 0; i < l; i++)s[i] = t.getUint32(i << 2)
          s[data.length >> 2] |= 0x80 << (24 - (data.length & 3) * 8)
          s[l - 1] = data.length << 3
          var w = [], f = [function () {return m[1] & m[2] | ~m[1] & m[3] },
            function () { return m[1] ^ m[2] ^ m[3] },
            function () { return m[1] & m[2] | m[1] & m[3] | m[2] & m[3] },
            function () { return m[1] ^ m[2] ^ m[3] }
          ], rol = function (n, c) {return n << c | n >>> (32 - c) },
            k = [1518500249, 1859775393, -1894007588, -899497514],
            m = [1732584193, -271733879, null, null, -1009589776]
          m[2] = ~m[0], m[3] = ~m[1]
          for (i = 0; i < s.length; i += 16) {var o = m.slice(0)
            for (j = 0; j < 80; j++)
              w[j] = j < 16 ? s[i + j] : rol(w[j - 3] ^ w[j - 8] ^ w[j - 14] ^ w[j - 16], 1),
                t = rol(m[0], 5) + f[j / 20 | 0]() + m[4] + w[j] + k[j / 20 | 0] | 0,
                m[1] = rol(m[1], 30), m.pop(), m.unshift(t)
            for (j = 0; j < 5; j++)m[j] = m[j] + o[j] | 0
          }
          t = new DataView(new Uint32Array(m).buffer)
          for (var i = 0; i < 5; i++)m[i] = t.getUint32(i << 2)
        
          var hex = Array.prototype.map.call(new Uint8Array(new Uint32Array(m).buffer), function (e) {return (e < 16 ? "0" : "") + e.toString(16)
          }).join("")
          return hex
    }
sha(123456); // 7c4a8d09ca3762af61e59520943dc26494f8941b