function repeat(str, n) { let res = ''; while(n) { if(n % 2 === 1) { res += str; } if(n > 1) { str += str; } n >>= 1; } return res }; //repeat('123',3) ==> 123123123
28、dateFormater：格式化时间
function dateFormater(formater, t){ let date = t ? new Date(t) : new Date(), Y = date.getFullYear() + '', M = date.getMonth() + 1, D = date.getDate(), H = date.getHours(), m = date.getMinutes(), s = date.getSeconds(); return formater.replace(/YYYY|yyyy/g,Y) .replace(/YY|yy/g,Y.substr(2,2)) .replace(/MM/g,(M<10?'0':'') + M) .replace(/DD/g,(D<10?'0':'') + D) .replace(/HH|hh/g,(H<10?'0':'') + H) .replace(/mm/g,(m<10?'0':'') + m) .replace(/ss/g,(s<10?'0':'') + s) } // dateFormater('YYYY-MM-DD HH:mm', t) ==> 2019-06-26 18:30 // dateFormater('YYYYMMDDHHmm', t) ==> 201906261830
29、dateStrForma：将指定字符串由一种时间格式转化为另一种
from的格式应对应str的位置
function dateStrForma(str, from, to){ //'20190626' 'YYYYMMDD' 'YYYY年MM月DD日' str += '' let Y = '' if(~(Y = from.indexOf('YYYY'))){ Y = str.substr(Y, 4) to = to.replace(/YYYY|yyyy/g,Y) }else if(~(Y = from.indexOf('YY'))){ Y = str.substr(Y, 2) to = to.replace(/YY|yy/g,Y) } let k,i ['M','D','H','h','m','s'].forEach(s =>{ i = from.indexOf(s+s) k = ~i ? str.substr(i, 2) : '' to = to.replace(s+s, k) }) return to } // dateStrForma('20190626', 'YYYYMMDD', 'YYYY年MM月DD日') ==> 2019年06月26日 // dateStrForma('121220190626', '----YYYYMMDD', 'YYYY年MM月DD日') ==> 2019年06月26日 // dateStrForma('2019年06月26日', 'YYYY年MM月DD日', 'YYYYMMDD') ==> 20190626 // 一般的也可以使用正则来实现 //'2019年06月26日'.replace(/(\d{4})年(\d{2})月(\d{2})日/, '$1-$2-$3') ==> 2019-06-26
30、getPropByPath：根据字符串路径获取对象属性 : 'obj[0].count'
function getPropByPath(obj, path, strict) { let tempObj = obj; path = path.replace(/\[(\w+)\]/g, '.$1'); //将[0]转化为.0 path = path.replace(/^\./, ''); //去除开头的. let keyArr = path.split('.'); //根据.切割 let i = 0; for (let len = keyArr.length; i < len - 1; ++i) { if (!tempObj && !strict) break; let key = keyArr[i]; if (key in tempObj) { tempObj = tempObj[key]; } else { if (strict) {//开启严格模式，没找到对应key值，抛出错误 throw new Error('please transfer a valid prop path to form item!'); } break; } } return { o: tempObj, //原始数据 k: keyArr[i], //key值 v: tempObj ? tempObj[keyArr[i]] : null // key值对应的值 }; };
31、GetUrlParam：获取Url参数，返回一个对象
function GetUrlParam(){ let url = document.location.toString(); let arrObj = url.split("?"); let params = Object.create(null) if (arrObj.length > 1){ arrObj = arrObj[1].split("&"); arrObj.forEach(item=>{ item = item.split("="); params[item[0]] = item[1] }) } return params; } // ?a=1&b=2&c=3 ==> {a: "1", b: "2", c: "3"}
32、downloadFile：base64数据导出文件，文件下载
function downloadFile(filename, data){ let DownloadLink = document.createElement('a'); if ( DownloadLink ){ document.body.appendChild(DownloadLink); DownloadLink.style = 'display: none'; DownloadLink.download = filename; DownloadLink.href = data; if ( document.createEvent ){ let DownloadEvt = document.createEvent('MouseEvents'); DownloadEvt.initEvent('click', true, false); DownloadLink.dispatchEvent(DownloadEvt); } else if ( document.createEventObject ) DownloadLink.fireEvent('onclick'); else if (typeof DownloadLink.onclick == 'function' ) DownloadLink.onclick(); document.body.removeChild(DownloadLink); } }
33、toFullScreen：全屏
function toFullScreen(){ let elem = document.body; elem.webkitRequestFullScreen ? elem.webkitRequestFullScreen() : elem.mozRequestFullScreen ? elem.mozRequestFullScreen() : elem.msRequestFullscreen ? elem.msRequestFullscreen() : elem.requestFullScreen ? elem.requestFullScreen() : alert("浏览器不支持全屏"); }
34、exitFullscreen：退出全屏