let myString = "John Doe"; if (typeof myString === "string") { console.log("This variable is a string"); } else { console.log("This variable is not a string"); } Indeed, the myString is a string: This variable is a string Note: Even if the variable contains a number th...
number string bigint symbol object null (typeof() shows as object) function (a special type of object) To verify if a variable is a number, we simply we need to check if the value returned by typeof() is "number". Let's try it out on test variables: Free eBook: Git Essentials ...
c# Check registry if program is installed if yes get install location ? C# Check to make sure first character in a string is a letter C# check username if already exists from database C# Class - USB Port Enabled/Disabled Status Detection C# class for JSON is resulting a Null Reference E...
Check if a string is null or empty in XSLT 多条件查询 string.Format("/root/deviceList//item/guid[{0}]", strBuilder.ToString()) "/root/deviceList//item/guid[text()=\"h\" or text()=\"a\" or text()=\"c\"]"谓词嵌套var nodes = xmlDoc.SelectNodes(string.Format("/root/device...
if (Math.sign(number) > 0) { // Positive } else { // Negative } Indeed, if you're just checking the boolean status, then I'd just use the comparative operator instead of using Math.sign. But where Math.sign shines is it returns a number value. This means you can do ...
var reg= /[\u0391-\uFFE5]/g;if(reg.test(name.value)) { alert(str); name.focus();returntrue; }returnfalse; }//---判断是否有sql非法字符---function isSqlCharacter(name, str) { str= str || "您提交的信息中有非法字符。";//var namevalue = name.value.toLowerCase() ;//把所有的...
{ // 通用 controlId: Number, // 编号,区别同一个表单里的其他控件 colName: String, // 字段名称 controlType: Number, // 用类型编号表示type isClear: { // isClear 连续添加时是否恢复默认值 type: Boolean, default: false }, defaultValue: String, // 默认值 autofocus: { // 是否自动获得...
Check if mobile browser, based on useragent string. Example varmobile=require('is-mobile');console.log(mobile());// => false API mobile({ [ua], [tablet], [featureDetect] }) Returns true if a mobile browser is being used. If you don't specifyopts.uait will usenavigator.userAgent. ...
(num)){intvalue=0;while(num>0){value+=Math.pow(num%10,2);num/=10;}num=value;}returnnum==1;}publicstaticvoidmain(String[]args){System.out.print("Input a number: ");intnum=newScanner(System.in).nextInt();System.out.println(isHappy_number(num)?"Happy Number":"Unhappy Number");...
check if input is integer or string Check if linq result is null. check if the data column and the data row have the same value in a datatable check if the datarow has values in datatable check if the result is integer or not check if variable is number in C# Check if vb.net...