JS公共類庫(工具類)

1. 時間格式化

function formatTime(time, cFormat) {
    if (arguments.length === 0) return null
    if ((time + '').length === 10) {
        time = +time * 1000
    }

    var format = cFormat || '{y}-{m}-{d} {h}:{i}:{s}', date
    if (typeof time === 'object') {
        date = time
    } else {
        date = new Date(time)
    }

    var formatObj = {
        y: date.getFullYear(),
        m: date.getMonth() + 1,
        d: date.getDate(),
        h: date.getHours(),
        i: date.getMinutes(),
        s: date.getSeconds(),
        a: date.getDay()
    }
    var time_str = format.replace(/{(y|m|d|h|i|s|a)+}/g, (result, key) => {
        var value = formatObj[key]
        if (key === 'a') return ['一', '二', '三', '四', '五', '六', '日'][value - 1]
        if (result.length > 0 && value < 10) {
            value = '0' + value
        }
        return value || 0
    })
    return time_str
}
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2. 獲取某月有多少天

function getMonthOfDay (time) {
    var date = new Date(time)
    var year = date.getFullYear()
    var mouth = date.getMonth() + 1
    var days

    //當月份爲二月時，根據閏年仍是非閏年判斷天數
    if (mouth == 2) {
        days = year % 4 == 0 ? 29 : 28
    } else if (mouth == 1 || mouth == 3 || mouth == 5 || mouth == 7 || mouth == 8 || mouth == 10 || mouth == 12) {
        //月份爲：1,3,5,7,8,10,12 時，爲大月.則天數爲31；
        days = 31
    } else {
        //其餘月份，天數爲：30.
        days = 30
    }
    return days
}
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3. 數組排序

/**
 * @param  {arr} 數組
 * @param  {type} 1：從小到大   2：從大到小   3：隨機
 * @return {Array}
 */
function sort (arr, type = 1) {
    return arr.sort( (a, b) => {
        switch(type) {
            case 1:
                return a - b;
            case 2:
                return b - a;
            case 3:
                return Math.random() - 0.5;
            default:
                return arr;
        }
    })
}
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4. 數組去重

function unique (arr) {
    if ( Array.hasOwnProperty('from') ) {
        return Array.from(new Set(arr));
    }else{
        var n = {},r=[]; 
        for(var i = 0; i < arr.length; i++){
            if (!n[arr[i]]){
                n[arr[i]] = true; 
                r.push(arr[i]);
            }
        }
        return r;
    }
}
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5. 兩個集合並集

function union (a, b) {
    var newArr = a.concat(b);
    return unique(newArr);
}
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6. 兩個集合交集

function intersect (a, b) {
    var _this = this;
    a = unique(a);
    return a.map(item => {
        return b.includes(item) ? b : null
    })
}
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7. 貨幣格式化

function currency (value, currency, decimals) => {
    value = parseFloat(value)
    if (!isFinite(value) || (!value && value !== 0)) return ''
    currency = currency != null ? currency : '$'
    decimals = decimals != null ? decimals : 2
    var stringified = Math.abs(value).toFixed(decimals)
    var _int = decimals
      ? stringified.slice(0, -1 - decimals)
      : stringified
    var i = _int.length % 3
    var head = i > 0
      ? (_int.slice(0, i) + (_int.length > 3 ? ',' : ''))
      : ''
    var _float = decimals
      ? stringified.slice(-1 - decimals)
      : ''
    var sign = value < 0 ? '-' : ''
    return sign + currency + head +
      _int.slice(i).replace(digitsRE, '$1,') +
      _float
  },
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8.長文本截斷方法

function textEllipsis (value, maxLength = 12) {
    if (!isString(value)) { return value }
    if (value.length > maxLength) {
      return `${value.slice(0, maxLength - 3)}...${value.slice(value.length - 3, value.length)}`
    } else {
      return value
    }
  }
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判斷參數是不是其中之一

function oneOf (value, validList) {
  for (let i = 0; i < validList.length; i++) {
    if (value === validList[i]) {
      return true
    }
  }
  return false
}
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deepCopy

function deepCopy (data) {
  const t = typeOf(data)
  let o

  if (t === 'array') {
    o = []
  } else if (t === 'object') {
    o = {}
  } else {
    return data
  }

  if (t === 'array') {
    for (let i = 0; i < data.length; i++) {
      o.push(deepCopy(data[i]))
    }
  } else if (t === 'object') {
    for (let i in data) {
      o[i] = deepCopy(data[i])
    }
  }
  return o
}
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JS提交表單

const JSForm = ({ url = '', params = {}, type = 'POST'}) => {
  let form = document.createElement('form')
  document.body.appendChild(form)

  for (let item in params) {
    let input = document.createElement('input')
    input.type = 'hidden'
    input.name = item
    input.value = params[item]
    form.appendChild(input)
  }
  form.method = type
  form.action = url
  form.submit()
  document.body.removeChild(form)
}
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獲取query的值

const getQueryString = name => {
  let reg = new RegExp("(^|&)" + name + "=([^&]*)(&|$)", "i");
  let r = window.location.search.substr(1).match(reg);
  if (r != null) return unescape(r[2]); return null;
}
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