typeof - JavaScript | MDN - MDN Web Docs
WebSep 12, 2023 · The typeof operator returns a string indicating the type of the operand's value. Try it. Syntax. js. typeof operand. Parameters. operand. An expression representing the object or primitive whose type is to be returned. Description. The following table summarizes the possible return values of typeof.
JavaScript typeof - W3Schools
WebYou can use the typeof operator to find the data type of a JavaScript variable. Example. typeof "John" // Returns "string" typeof 3.14 // Returns "number" typeof NaN // Returns "number" typeof false // Returns "boolean" typeof [1,2,3,4] // Returns "object" typeof {name:'John', age:34} // Returns "object" typeof new Date () // Returns "object"
JavaScript TypeOf – How to Check the Type of a Variable or …
WebNov 9, 2020 · The typeof operator takes only one operand (a unary operator). It evaluates the type of the operand and returns the result as a string. Here is how you use it when you're evaluating the type of a number, 007. typeof 007; // returns 'number'.
JavaScript typeof
WebThe following example shows how to use the typeof operator with values of various types: console .log(type); // 'string'. console .log(type); // 'number'. console .log(type); // 'bigint'. console .log(type); // 'boolean'. console .log(type); …
JavaScript typeof Operator - Programiz
WebThe typeof operator returns the type of variables and values. For example, const a = 9; console.log(typeof a); // number console.log(typeof '9'); // string console.log(typeof false); // boolean. Syntax of typeof Operator. The syntax of typeof operator is: typeof operand. Here, operand is a variable name or a value. typeof Types.
typeof - MDN Web Docs
Web1. console.log(typeof 42); 2. // expected output: "number" 3. 4. console.log(typeof 'blubber'); 5. // expected output: "string" 6. 7. console.log(typeof true); 8. // expected output: "boolean" 9. 10. console.log(typeof declaredButUndefinedVariable); 11. // expected output: "undefined"; 12. Run ›. Reset. Syntax.
JavaScript typeof : Understanding type checking in JavaScript
WebSep 27, 2018 · Generic type checking. As seen with arrays, the Object.prototype.toString() method can be very useful for checking the object type of any JavaScript value. When it is invoked on a value using call() or apply(), it returns the object type in the format: [object Type], where Type is the object type.
JavaScript Type Checking – How to Check Type in JS with typeof()
WebDec 9, 2022 · The typeof operator accepts a single operand (a unary operator) and determines the operand's type. There are two ways you can use the typeof operator. You can evaluate a single value or an expression: typeof(expression); // Or typeof value; The typeof operator will return the type as a string, meaning “number”, “string”, "boolean”, and …
Finding Variable Type in JavaScript - Stack Overflow
Web12 Answers. Sorted by: 305. Use typeof: > typeof "foo" "string" > typeof true. "boolean" > typeof 42. "number" So you can do: if(typeof bar === 'number') { //whatever. } Be careful though if you define these primitives with their object wrappers (which you should never do, use literals where ever possible): > typeof new Boolean(false) "object"
The `typeof` Operator in JavaScript - Mastering JS
WebThe typeof Operator tells you the type of a value - whether the value is a number, string, object, etc. Here's what you need to know.
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