javascript find type of variable
> typeof "foo"
"string"
> typeof true
"boolean"
> typeof 42
"number"
if(typeof bar === 'number') {
//whatever
}javascript find type of variable
> typeof "foo"
"string"
> typeof true
"boolean"
> typeof 42
"number"
if(typeof bar === 'number') {
//whatever
}check data type in js
typeof("string"); //string
typeof(123); //numbertype of javascript
//typeof() will return the type of value in its parameters.
//some examples of types: undefined, NaN, number, string, object, array
//example of a practical usage
if (typeof(value) !== "undefined") {//also, make sure that the type name is a string
//execute code
}js typeof number
console.log(typeof 93);
// Output = "number"
console.log(typeof 'Maximum');
// Output = 'string'
console.log(typeof false);
// Output = "boolean"
console.log(typeof anUndeclaredVariable);
// Output = "undefined"typeof
// Numbers
typeof 37 === 'number';
typeof 3.14 === 'number';
typeof(42) === 'number';
typeof Math.LN2 === 'number';
typeof Infinity === 'number';
typeof NaN === 'number'; // Despite being "Not-A-Number"
typeof Number('1') === 'number'; // Number tries to parse things into numbers
typeof Number('shoe') === 'number'; // including values that cannot be type coerced to a number
typeof 42n === 'bigint';
// Strings
typeof '' === 'string';
typeof 'bla' === 'string';
typeof `template literal` === 'string';
typeof '1' === 'string'; // note that a number within a string is still typeof string
typeof (typeof 1) === 'string'; // typeof always returns a string
typeof String(1) === 'string'; // String converts anything into a string, safer than toString
// Booleans
typeof true === 'boolean';
typeof false === 'boolean';
typeof Boolean(1) === 'boolean'; // Boolean() will convert values based on if they're truthy or falsy
typeof !!(1) === 'boolean'; // two calls of the ! (logical NOT) operator are equivalent to Boolean()
// Symbols
typeof Symbol() === 'symbol'
typeof Symbol('foo') === 'symbol'
typeof Symbol.iterator === 'symbol'
// Undefined
typeof undefined === 'undefined';
typeof declaredButUndefinedVariable === 'undefined';
typeof undeclaredVariable === 'undefined';
// Objects
typeof {a: 1} === 'object';
// use Array.isArray or Object.prototype.toString.call
// to differentiate regular objects from arrays
typeof [1, 2, 4] === 'object';
typeof new Date() === 'object';
typeof /regex/ === 'object'; // See Regular expressions section for historical results
// The following are confusing, dangerous, and wasteful. Avoid them.
typeof new Boolean(true) === 'object';
typeof new Number(1) === 'object';
typeof new String('abc') === 'object';
// Functions
typeof function() {} === 'function';
typeof class C {} === 'function';
typeof Math.sin === 'function';javascript check type of variable var
// You can use the built-in method 'typeof' in order to check the variable datatype
//examples:
typeof "hello" // "string"
//or
var a = 1;
typeof(a);
//the output will be > 'number'Copyright © 2021 Codeinu
Forgot your account's password or having trouble logging into your Account? Don't worry, we'll help you to get back your account. Enter your email address and we'll send you a recovery link to reset your password. If you are experiencing problems resetting your password contact us
