javascript 常用方法1

js 常用方法

(1)startWith

var startsWith = function (str, regex) {
    if (regex == undefined || str == undefined || (!str) || (!regex)) {
        return false;
    }
    return str.indexOf(regex) == 0;
};

测试:

console.log(startsWith('123abc',''));

(2)trim

var trim = function (str) { //
    if (typeof str === "object") {
        return str;
    }
    if (str == null || str == "" || str == undefined) {
        return str;
    }
    if (typeof str === "number") {
        return str;
    }
    return str.replace(/(^\s*)|(\s*$)/g, "");
};

 应用:

var cssColor2Hex = function (cssColor) {
    var stringObj = cssColor.replace(/RGB[\s]*\(([\w,\s]+)\)[\s]*/i, "$1");
    //console.log(stringObj);
    var arr = stringObj.split(',');
    var r = trim(arr[0]);
    var g = trim(arr[1]);
    var b = trim(arr[2]);
    var rHex = to2Hex(r);
    var gHex = to2Hex(g);
    var bHex = to2Hex(b);
    return (rHex + gHex + bHex);
};

(3)是否包含特殊字符

/***
 * 判断是否包含特殊字符
 * @param str
 * @returns {boolean}
 */
var containsSpecialCharacter = function (str) {
    var reg = /[@#$?*！？]/g;
    return reg.test(str);
};

 应用:

if (containsSpecialCharacter(orgFullName_val)) {
        setErrerMessageAndFocus($error_create_org, $orgFullName, '不能包含非法字符');
        return;
    }

(4)动态加载js脚本文件

/***
 * 动态加载javascript 脚本文件
 * @param url
 * @param callback
 */
function loadJs(url, callback) {
    var done = false;
    var script = document.createElement('script');
    script.type = 'text/javascript';
    script.language = 'javascript';
    script.charset = "utf-8";
    script.src = url;
    //script.setAttribute('src', url);
    script.onload = script.onreadystatechange = function () {
        if (!done && (!script.readyState || script.readyState == 'loaded' || script.readyState == 'complete')) {
            done = true;
            script.onload = script.onreadystatechange = null;
            if (callback) {
                callback.call(script);
            }
        }
    };
    document.getElementsByTagName("head")[0].appendChild(script);
};

 应用:

readyCallBack=function(){
			$(document).ready(function(){
				// 键盘按下时，清理错误提示
				clearError=function(){
					$(".errorMessage").hide(1000);
				};
				$(document).bind("keypress",clearError);
				var loginStatus = document.getElementById("loginStatus");
				if(loginStatus.value==<%=LoginConstants.ACCOUNT_LOGINED%>){
					jAlert("<s:text name='login.user.sameLogined' />",null,function(){window.location.href='<s:url action="home"/>';});
				}
			});
			loadJs('<s:url value="/js/jquery.bgiframe.js" />');
			loadJs('<s:url value="/js/alert/jquery.alerts.js" />');
		};
		loadJs('<s:url value="/js/jquery-1.9.0.min.js" />',readyCallBack);

 参考: