自定义javascript函数

// 一些常用的函数写法，可以作为参考

<script type="text/javascript">
    // 定义 trim函数
    function trim(ostr) {
        return ostr.replace(/^\s+|\s+$/g, "");
    }
    // 定义类型判断函数
    function isNumber(s) {
        return !isNaN(s);
    }
    function isString(s) {
        return typeof s == "string";
    }
    function isBoolean(s) {
        return typeof s == "boolean";
    }
    function isFunction(s) {
        return typeof s == "function";
    }
    function isNull(s) {
        return s == null;
    }
    function isUndefined(s) {
        return typeof s == "undefined";
    }
    function isEmpty(s) {
        return /^\s*$/.test(s);
    }
    function isArray(s) {
        return s instanceof Array;
    }
    // 定义 get 和$函数
    function get(node) {
        node = typeof node == "string" ? document.getElementById(node) : node;
        return node;
    }
    function $(node) {
        node = typeof node == "string" ? document.getElementById(node) : node;
        return node;
    }
    // 定义 getElementsByClassName 函数
    function getElementsByClassName(str, root, tag) {
        if (root) {
            root = typeof root == "string" ? document.getElementById(root) : root;
        } else {
            root = document.body;
        }
        tag = tag || "*";
        var els = root.getElementsByTagName(tag),arr = [];
        for (var i = 0,n = els.length; i < n; i++) {
            for (var j = 0,k = els[i].className.split(" "),l = k.length; j < l; j++) {
                if (k[j] == str) {
                    arr.push(els[i]);
                    break;
                }
            }
        }
        return arr;
    }
</script>

 

======================使用命名空间===========================

<script type="text/javascript">
    // 使用命名空间
    var GLOBAL = {};
    GLOBAL.namespace = function(str) {
        var arr = str.split("."),o = GLOBAL;
        for (i = (arr[0] == "GLOBAL") ? 1 : 0; i < arr.length; i++) {
            o[arr[i]] = o[arr[i]] || {};
            o = o[arr[i]];
        }
    }
    //Dom相关
    GLOBAL.namespace("Dom");
    GLOBAL.Dom.getNextNode = function(node) {
        node = typeof node == "string" ? document.getElementById(node) : node;
        var nextNode = node.nextSibling;
        if (!nextNode) return null;
        if (!document.all) {
            while (true) {
                if (nextNode.nodeType == 1) {
                    break;
                } else {
                    if (nextNode.nextSibling) {
                        nextNode = nextNode.nextSibling;
                    } else {
                        break;
                    }
                }
            }
        }
        return nextNode;
    };
    GLOBAL.Dom.setOpacity = function(node, level) {
        node = typeof node == "string" ? document.getElementById(node) : node;
        if (document.all) {
            node.style.filter = 'alpha(opacity=' + level + ')';
        } else {
            node.style.opacity = level / 100;
        }
    }
    GLOBAL.Dom.get = function(node) {
        node = typeof node == "string" ? document.getElementById(node) : node;
        return node;
    }
    GLOBAL.Dom.getElementsByClassName = function(str, root, tag) {
        if (root) {
            root = typeof root == "string" ? document.getElementById(root) : root;
        } else {
            root = document.body;
        }
        tag = tag || "*";
        var els = root.getElementsByTagName(tag),arr = [];
        for (var i = 0,n = els.length; i < n; i++) {
            for (var j = 0,k = els[i].className.split(" "),l = k.length; j < l; j++) {
                if (k[j] == str) {
                    arr.push(els[i]);
                    break;
                }
            }
        }
        return arr;
    }
    //Event相关
    GLOBAL.namespace("Event");
    GLOBAL.Eevent.getEventTarget = function(e) {
        e = window.event || e;
        return e.srcElement || e.target;
    }
    GLOBAL.Event.stopPropagation = function(e) {
        e = window.event || e;
        if (document.all) {
            e.cancelBubble = true;
        } else {
            e.stopPropagation();
        }
    }
    GLOBAL.Event.on = function(node, eventType, handler) {
        node = typeof node == "string" ? document.getElementById(node) : node;
        if (document.all) {
            node.attachEvent("on" + eventType, handler);
        } else {
            node.addEventListener(eventType, handler, false);
        }
    }

    //Lang相关
    GLOBAL.namespace("Lang");
    GLOBAL.Lang.trim = function(ostr) {
        return ostr.replace(/^\s+|\s+$/g, "");
    }
    GLOBAL.Lang.isNumber = function(s) {
        return !isNaN(s);
    }
    GLOBAL.Lang.extend = function(subClass, superClass) {
        var F = function() {
        };
        F.prototype = superClass.prototype;
        subClass.prototype = new F();
        subClass.prototype.constructor = subClass;
        subClass.superclass = superClass.prototype;
        if (superClass.prototype.constructor == Object.prototype.constructor) {
            superClass.prototype.constructor = superClass;
        }
    }

</script>