js倒計時程式碼最簡單的_32個史上最有用的js程式碼

阿新 • • 發佈：2020-12-11

1. 原生JavaScript實現字串長度擷取

function cutstr(str, len) {
    var temp;
    var icount = 0;
    var patrn = /[^x00-xff]/;
    var strre = "";
    for (var i = 0; i < str.length; i++) {
        if (icount < len - 1) {
            temp = str.substr(i, 1);
            if (patrn.exec(temp) == null) {
                icount = icount + 1
            } else {
                icount = icount + 2
            }
            strre += temp
        } else {
            break
        }
    }
    return strre + "..."
}

2. 原生JavaScript獲取域名主機

function getHost(url) {
    var host = "null";
    if(typeof url == "undefined"|| null == url) {
        url = window.location.href;
    }
    var regex = /^w+://([^/]*).*/;
    var match = url.match(regex);
    if(typeof match != "undefined" && null != match) {
        host = match[1];
    }
    return host;
}

3. 原生JavaScript清除空格

String.prototype.trim = function() {
     var reExtraSpace = /^s*(.*?)s+$/;
     return this.replace(reExtraSpace, "$1")
}

4.原生JavaScript替換全部

String.prototype.replaceAll = function(s1, s2) {
     return this.replace(new RegExp(s1, "gm"), s2)
 }

5.原生JavaScript轉義html標籤

function HtmlEncode(text) {
     return text.replace(/&/g, '&amp').replace(/"/g, '&quot;').replace(/</g, '&lt;').replace(/>/g, '&gt;')
 }

6. 原生JavaScript還原html標籤

function HtmlDecode(text) {
     return text.replace(/&amp;/g, '&').replace(/&quot;/g, '"').replace(/&lt;/g, '<').replace(/&gt;/g, '>')
 }

7.原生JavaScript時間日期格式轉換

Date.prototype.Format = function(formatStr) {
    var str = formatStr;
    var Week = ['日', '一', '二', '三', '四', '五', '六'];
    str = str.replace(/yyyy|YYYY/, this.getFullYear());
    str = str.replace(/yy|YY/, (this.getYear() % 100) > 9 ? (this.getYear() % 100).toString() : '0' + (this.getYear() % 100));
    str = str.replace(/MM/, (this.getMonth() + 1) > 9 ? (this.getMonth() + 1).toString() : '0' + (this.getMonth() + 1));
    str = str.replace(/M/g, (this.getMonth() + 1));
    str = str.replace(/w|W/g, Week[this.getDay()]);
    str = str.replace(/dd|DD/, this.getDate() > 9 ? this.getDate().toString() : '0' + this.getDate());
    str = str.replace(/d|D/g, this.getDate());
    str = str.replace(/hh|HH/, this.getHours() > 9 ? this.getHours().toString() : '0' + this.getHours());
    str = str.replace(/h|H/g, this.getHours());
    str = str.replace(/mm/, this.getMinutes() > 9 ? this.getMinutes().toString() : '0' + this.getMinutes());
    str = str.replace(/m/g, this.getMinutes());
    str = str.replace(/ss|SS/, this.getSeconds() > 9 ? this.getSeconds().toString() : '0' + this.getSeconds());
    str = str.replace(/s|S/g, this.getSeconds());
    return str
}

8.原生JavaScript判斷是否為數字型別

function isDigit(value) {
    var patrn = /^[0-9]*$/;
    if (patrn.exec(value) == null || value == "") {
        return false
    } else {
        return true
    }
}

9.原生JavaScript設定cookie值

function setCookie(name, value, Hours) {
        var d = new Date();
    var offset = 8;
    var utc = d.getTime() + (d.getTimezoneOffset() * 60000);
    var nd = utc + (3600000 * offset);
    var exp = new Date(nd);
    exp.setTime(exp.getTime() + Hours * 60 * 60 * 1000);
    document.cookie = name + "=" + escape(value) + ";path=/;expires=" + exp.toGMTString() + ";domain=360doc.com;"
}

10.原生JavaScript獲取cookie值

function getCookie(name) {
 var arr = document.cookie.match(new RegExp("(^| )" + name + "=([^;]*)(;|$)"));
 if (arr != null) return unescape(arr[2]);
 return null
}

11.原生JavaScript加入收藏夾

 function AddFavorite(sURL, sTitle) {
     try {
         window.external.addFavorite(sURL, sTitle)
     } catch(e) {
         try {
             window.sidebar.addPanel(sTitle, sURL, "")
         } catch(e) {
             alert("加入收藏失敗，請使用Ctrl+D進行新增")
         }
     }
 }

12.原生JavaScript設為首頁

function setHomepage() {
        if (document.all) {
            document.body.style.behavior = 'url(#default#homepage)';
            document.body.setHomePage('http://***')
        } else if (window.sidebar) {
            if (window.netscape) {
                try {
                    netscape.security.PrivilegeManager.enablePrivilege("UniversalXPConnect")
                } catch(e) {
                    alert("該操作被瀏覽器拒絕，如果想啟用該功能，請在位址列內輸入 about:config,然後將項 signed.applets.codebase_principal_support 值該為true")
                }
            }
            var prefs = Components.classes['@mozilla.org/preferences-service;1'].getService(Components.interfaces.nsIPrefBranch);
            prefs.setCharPref('browser.startup.homepage', 'http://***')
        }
    }

13.原生JavaScript判斷IE6

var ua = navigator.userAgent.toLowerCase();var isIE6 = ua.indexOf("msie 6") > -1;if (isIE6) {
    try {
        document.execCommand("BackgroundImageCache", false, true)
    } catch(e) {}
}

14.原生JavaScript載入樣式檔案

function LoadStyle(url) {
    try {
        document.createStyleSheet(url)
    } catch(e) {
        var cssLink = document.createElement('link');
        cssLink.rel = 'stylesheet';
        cssLink.type = 'text/css';
        cssLink.href = url;
        var head = document.getElementsByTagName('head')[0];
        head.appendChild(cssLink)
    }
}

15.原生JavaScript返回指令碼內容

function evalscript(s) {
    if(s.indexOf('<script') == -1) return s;
    var p = /<script[^>]*?>([^x00]*?)</script>/ig;
    var arr = [];
    while(arr = p.exec(s)) {
        var p1 = /<script[^>]*?src="([^>]*?)"[^>]*?(reload="1")?(?:charset="([w-]+?)")?></script>/i;
        var arr1 = [];
        arr1 = p1.exec(arr[0]);
        if(arr1) {
            appendscript(arr1[1], '', arr1[2], arr1[3]);
        } else {
            p1 = /<script(.*?)>([^x00]+?)</script>/i;
            arr1 = p1.exec(arr[0]);
            appendscript('', arr1[2], arr1[1].indexOf('reload=') != -1);
        }
    }
    return s;
}

16.原生JavaScript清除指令碼內容

function stripscript(s) {
     return s.replace(/<script.*?>.*?</script>/ig, '');
 }

17.原生JavaScript動態載入指令碼檔案

function appendscript(src, text, reload, charset) {
    var id = hash(src + text);
    if(!reload && in_array(id, evalscripts)) return;
    if(reload && $(id)) {
        $(id).parentNode.removeChild($(id));
    }
 
    evalscripts.push(id);
    var scriptNode = document.createElement("script");
    scriptNode.type = "text/javascript";
    scriptNode.id = id;
    scriptNode.charset = charset ? charset : (BROWSER.firefox ? document.characterSet : document.charset);
    try {
        if(src) {
            scriptNode.src = src;
            scriptNode.onloadDone = false;
            scriptNode.onload = function () {
                scriptNode.onloadDone = true;
                JSLOADED[src] = 1;
            };
            scriptNode.onreadystatechange = function () {
                if((scriptNode.readyState == 'loaded' || scriptNode.readyState == 'complete') && !scriptNode.onloadDone) {
                    scriptNode.onloadDone = true;
                    JSLOADED[src] = 1;
                }
            };
        } else if(text){
            scriptNode.text = text;
        }
        document.getElementsByTagName('head')[0].appendChild(scriptNode);
    } catch(e) {}
}

18.原生JavaScript返回按ID檢索的元素物件

 function $(id) {
     return !id ? null : document.getElementById(id);
 }

19.原生JavaScript返回瀏覽器版本內容

function browserVersion(types) {
    var other = 1;
    for(i in types) {
        var v = types[i] ? types[i] : i;
        if(USERAGENT.indexOf(v) != -1) {
            var re = new RegExp(v + '(/|s)([d.]+)', 'ig');
            var matches = re.exec(USERAGENT);
            var ver = matches != null ? matches[2] : 0;
            other = ver !== 0 && v != 'mozilla' ? 0 : other;
        }else {
            var ver = 0;
        }
        eval('BROWSER.' + i + '= ver');
    }
    BROWSER.other = other;
}

20.原生JavaScript元素顯示的通用方法

function $(id) {
    return !id ? null : document.getElementById(id);
}function display(id) {
    var obj = $(id);
    if(obj.style.visibility) {
        obj.style.visibility = obj.style.visibility == 'visible' ? 'hidden' : 'visible';
    } else {
        obj.style.display = obj.style.display == '' ? 'none' : '';
    }
}

21.原生JavaScript中有insertBefore方法,可惜卻沒有insertAfter方法?用如下函式實現

function insertAfter(newChild,refChild){ 
    var parElem=refChild.parentNode; 
    if(parElem.lastChild==refChild){ 
        refChild.appendChild(newChild); 
    }else{ 
        parElem.insertBefore(newChild,refChild.nextSibling); 
    } 
}

22.原生JavaScript中相容瀏覽器繫結元素事件

function addEventSamp(obj,evt,fn){ 
    if (obj.addEventListener) { 
        obj.addEventListener(evt, fn, false); 
    }else if(obj.attachEvent){ 
        obj.attachEvent('on'+evt,fn); 
    } 
}

23.原生JavaScript游標停在文字的後面，文字框獲得焦點時呼叫

function focusLast(){ 
    var e = event.srcElement; 
    var r =e.createTextRange(); 
    r.moveStart('character',e.value.length); 
    r.collapse(true); 
    r.select(); 
}

24.原生JavaScript檢驗URL連結是否有效

function getUrlState(URL){ 
    var xmlhttp = new ActiveXObject("microsoft.xmlhttp"); 
    xmlhttp.Open("GET",URL, false);  
    try{  
        xmlhttp.Send(); 
    }catch(e){
    }finally{ 
        var result = xmlhttp.responseText; 
        if(result){ 
            if(xmlhttp.Status==200){ 
                return(true); 
            }else{ 
                return(false); 
            } 
        }else{ 
            return(false); 
        } 
    } 
}

25.原生JavaScript格式化CSS樣式程式碼

function formatCss(s){//格式化程式碼
    s = s.replace(/s*([{}:;,])s*/g, "$1");
    s = s.replace(/;s*;/g, ";"); //清除連續分號
    s = s.replace(/,[s.#d]*{/g, "{");
    s = s.replace(/([^s]){([^s])/g, "$1 {nt$2");
    s = s.replace(/([^s])}([^n]*)/g, "$1n}n$2");
    s = s.replace(/([^s]);([^s}])/g, "$1;nt$2");
    return s;
}

26.原生JavaScript壓縮CSS樣式程式碼

function yasuoCss (s) {//壓縮程式碼
    s = s.replace(//*(.|n)*?*//g, ""); //刪除註釋
    s = s.replace(/s*([{}:;,])s*/g, "$1");
    s = s.replace(/,[s.#d]*{/g, "{"); //容錯處理
    s = s.replace(/;s*;/g, ";"); //清除連續分號
    s = s.match(/^s*(S+(s+S+)*)s*$/); //去掉首尾空白
    return (s == null) ? "" : s[1];
}

27.原生JavaScript獲取當前路徑

var currentPageUrl = "";if (typeof this.href === "undefined") {
    currentPageUrl = document.location.toString().toLowerCase();
}else {
    currentPageUrl = this.href.toString().toLowerCase();
}

28.原生JavaScriptIP轉成整型

function _ip2int(ip){
    var num = 0;
    ip = ip.split(".");
    num = Number(ip[0]) * 256 * 256 * 256 + Number(ip[1]) * 256 * 256 + Number(ip[2]) * 256 + Number(ip[3]);
    num = num >>> 0;
    return num;
}

29.原生JavaScript整型解析為IP地址

function _int2iP(num){
    var str;
    var tt = new Array();
    tt[0] = (num >>> 24) >>> 0;
    tt[1] = ((num << 8) >>> 24) >>> 0;
    tt[2] = (num << 16) >>> 24;
    tt[3] = (num << 24) >>> 24;
    str = String(tt[0]) + "." + String(tt[1]) + "." + String(tt[2]) + "." + String(tt[3]);
    return str;
}

30.原生JavaScript實現checkbox全選與全不選

function checkAll() {
    var selectall = document.getElementById("selectall");
    var allbox = document.getElementsByName("allbox");
    if (selectall.checked) {
        for (var i = 0; i < allbox.length; i++) {
            allbox[i].checked = true;
        }
    } else {
        for (var i = 0; i < allbox.length; i++) {
            allbox[i].checked = false;
        }
    }
}

31.原生JavaScript判斷是否移動裝置

function isMobile(){
    if (typeof this._isMobile === 'boolean'){
        return this._isMobile;
    }
    var screenWidth = this.getScreenWidth();
    var fixViewPortsExperiment = rendererModel.runningExperiments.FixViewport || rendererModel.runningExperiments.fixviewport;
    var fixViewPortsExperimentRunning = fixViewPortsExperiment && (fixViewPortsExperiment.toLowerCase() === "new");
    if(!fixViewPortsExperiment){
        if(!this.isAppleMobileDevice()){
            screenWidth = screenWidth/window.devicePixelRatio;
        }
    }
    var isMobileScreenSize = screenWidth < 600;
    var isMobileUserAgent = false;
    this._isMobile = isMobileScreenSize && this.isTouchScreen();
    return this._isMobile;
}

32.原生JavaScript判斷是否移動裝置訪問

 function isMobileUserAgent(){
    return (/iphone|ipod|android.*mobile|windows.*phone|blackberry.*mobile/i.test(window.navigator.userAgent.toLowerCase()));
 }