// NaN出现的原因:(Not a Number) // 操作两个类型不一致的数、用NaN值计算最终得到NaN、不合法运算(如0 / 0) let num = 0/0;if(isNaN(num)) { console.log("num为NaN!") } 2. 判断undefined let temp =undefined//方法一if(typeof(temp) == "undefined") { console.log("temp is undefined...
null ( non-value)空类型 , 只有显示声明null才能使用 NaN : (Not a Number 的缩写),如果给定的字符串不存在数值形式,函数会返回一个特殊的值 NaN。 代码语言:javascript 代码运行次数:0 运行 AI代码解释 parseInt("hello",10);// NaN"test"/123//把 NaN 作为参数进行任何数学运算,结果也会是 NaN:NaN+5...
注意:在计算失败时,显示的结果是 NaN (not a number) 代码语言:javascript 代码运行次数:0 运行 AI代码解释 // 算术运算符 console.log(1 + 2 * 3 / 2) // 4 let num = 10 console.log(num + 10) // 20 console.log(num + num) // 20 // 1. 取模(取余数) 使用场景: 用来判断某个数是...
JavaScript Code: // Define a function 'isEven' that checks if a number 'num' is evenconstisEven=num=>num%2===0;// Test cases to check if numbers are evenconsole.log(isEven(3));// false (3 is not even)console.log(isEven(32));// true (32 is even)console.log(isEven(1));// ...
Boolean(number); // true 虚值 在JavaScript中，有6个虚值。如果将其中任何一个字符串转换为Boolean，它将变为false 。false undefined null NaN "" (empty string)任何不为虚值的都会转换为true。示例 虚值的应用：!!false;// false !!undefined; // false !!null; // false !!NaN; // false !!0; ...
If a number is supplied, delay is applied to both hide/show Object structure is: delay: { "show": 500, "hide": 100 } html boolean false Insert HTML into the tooltip. If false, jQuery's text method will be used to insert content into the DOM. Use text if you're worried about XSS...
Delay showing and hiding the tooltip (ms) - does not apply to manual trigger type If a number is supplied, delay is applied to both hide/show Object structure is: delay: { "show": 500, "hide": 100 } html boolean false Insert HTML into the tooltip. If false, jQuery's text method ...
“Expected a number and instead saw ‘{a}’.”:“应该用数字代替’{a}’”, “‘{a}’ should not be greater than ‘{b}’.”:“‘{a}’不应该比’{b}’大”, “‘hasOwnProperty’ is a really bad name.”: “‘hasOwnProperty’是关键字”, ...
NaN is a JavaScript reserved word indicating that a number is not a legal number.Trying to do arithmetic with a non-numeric string will result in NaN (Not a Number):Example let x = 100 / "Apple"; Try it Yourself » However, if the string is numeric, the result will be a number...
A surprisingly high number of JavaScript developers fail to fully understand, and therefore fully leverage, the features of prototypal inheritance. Here’s a simple example: BaseObject=function(name) {if(typeofname !=="undefined") {this.name= name; }else{this.name='default'} }; ...