}if(TValue<0){alert(Describe+"项输入数字应大于等于0,请检查!");return(false); }//检查整型数字结束//检查实数if(Precision!=0&&!isFloat(TValue)) {alert(Describe+"项必须输入数字,请检查!");return(false); }if(Precision!=0&&isFloat(TValue)&&MaxLength!=0&&(DefiniteLengthMark==0||DefiniteLeng...
var s=parseFloat(trim(name.value));if(isNaN(s)) { alert(str); name.focus();returntrue; }elsereturnfalse; }//---检查输入的值,小数点后的位数---function checknumber(value, num, str) {if(value != "") {if(value.indexOf(".") > 0) { var temp= value.length - (value.indexOf("...
If isNaN() returns false, the value is a number.Another way is to use the typeof operator. It returns the 'number' string if you use it on a number value:typeof 1 //'number' const value = 2 typeof value //'number'So you can do a conditional check like this:const value = 2...
function isValidDate(dateString) { // 正则表达式验证日期格式 YYYY-MM-DD const datePattern = /^\d{4}-\d{2}-\d{2}$/; if (!datePattern.test(dateString)) { return false; // 格式不正确 } // 创建Date对象并验证 const date = new Date(dateString); if (isNaN(date.getTime())) { retu...
In React.js, you can check if a value is an integer or a string using JavaScript's typeof operator. The typeof operator returns a string indicating the type of the operand. To check if a value is an integer, you can use the Number.isInteger() method, whi
TheObject.fromEntries()transforms a list of key-value pairs into an object. I wrotea bookin which I share everything I know about how to become a better, more efficient programmer. You can use the search field on myHome Pageto filter through all of my articles. ...
I wrotea bookin which I share everything I know about how to become a better, more efficient programmer. You can use the search field on myHome Pageto filter through all of my articles. ShareShareShareShareShare Search for posts 0
Unfortunately, there is a bug in Firefox (will be fixed in version 78) that prevents this from being used universally. But if you can control your runtime environment and it supports it (e.g. Node.js), this is a straightforward, comprehensive solution. Atlernatively, XRegExp provides a po...
The Number.isFinite() function checks if the variable is a number, but also checks if it's a finite value. Therefore, it returns false on numbers that are NaN, Infinity or -Infinity. Let's test it out on the variables we've defined above: > Number.isFinite(intVar); true > Number...
if (typeof value !== 'undefined' && value) { //deal with value' }; It will cover cases where value was never defined, and also any of these: null undefined (value of undefined is not the same as a parameter that was never defined) 0 "" (empty string) fals...