为false时:空字符串 '' 、undefined、0、NAN、null 为true时:除上述false的情况都为true 此判断会经常应用于判断一个变量是否有返回的if 语句中 varo ={'name':'lee'};vara = ['reg','blue'];functioncheckBoolean(a){if(a){returntrue; }else{returnfalse; } } console.log(checkBoolean(''));//...
...你还应该确保对象实际上是一个对象,通过检查它的构造函数是对象对象: objectToCheck.constructor === Object Lodash是一个流行的库,它提供了isEmpty()函数判断是否是空对象...,简化了操作: _.isEmpty(objectToCheck) 类似的使用Object.entries方法,我们还可以使用Object.keys()和Object.values()来判断,判断...
使用getTime()方法将日期对象转换成毫秒。 如果日期对象非法,getTime方法将会返回NaN。...因此判断逻辑如下: function isValidDate(d) { return d instanceof Date && !isNaN(d); } 实际案例: if(! 12.9K11 js检查日期是否合法 检查日期是否合法 function CheckDateTime(str) { var reg = /^(\d+)-(\d...
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Looking for help? Check out the instructions for getting support.Release typesCurrent: Under active development. Code for the Current release is in the branch for its major version number (for example, v22.x). Node.js releases a new major version every 6 months, allowing for breaking changes...
Adds thesetLimitmethod to set the limit of the heap. It returnsNaNif the limit is negative, or NaN. This method is useful to check if the limit was set as expected. Improves tests and documentation. 2.4 Adds theindexOfmethod to find the first index of an element in the heap. ...
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"NumberIsNaN","Number","isNaN","EventEmitter","init","once","emitter","name","errorListener","err","removeListener","slice","eventTargetAgnosticAddListener","handler","flags","on","addErrorHandlerIfEventEmitter","_events","_eventsCount","_maxListeners","defaultMaxListeners","checkListener...
Math.js is an extensive math library for JavaScript and Node.js. It features a flexible expression parser with support for symbolic computation, comes with a large set of built-in functions and constants, and offers an integrated solution to work with di
js验证是否是合法日期: 代码语言:javascript 复制 functioncheck(date){return(newDate(date).getDate()==date.substring(date.length-2));}