1.判断变量是否为函数
function isFunction( obj ) {
return typeof obj === "function" && typeof obj.nodeType !== "number";
}
// Support: Chrome <=57, Firefox <=52
// In some browsers, typeof returns "function" for HTML <object> elements
// (i.e., `typeof document.createElement( "object" ) === "function"`).
// We don't want to classify *any* DOM node as a function.
2.判断变量是否是window
function isWindow( obj ) {
return obj != null && obj === obj.window;
}
