JavaScript in and instanceof operators Last Updated : 25 Nov, 2024 Comments Improve Suggest changes Like Article Like Report JavaScript Relational Operators are used to compare their operands and determine the relationship between them. They return a Boolean value (true or false) based on the comparison result.JavaScript in OperatorThe in-operator in JavaScript checks if a specified property exists in an object or if an element exists in an array. It returns a Boolean value. JavaScript let languages = ["HTML", "CSS", "JavaScript"]; // true (index 1 exists in the array) console.log(1 in languages); // false (index 3 doesn't exist in the array) console.log(3 in languages); Outputtrue false JavaScript const Data = { name: "Rahul", age: 21, city: "Noida" }; // true ("name" property exists in the object) console.log("name" in Data); // false ("gender" property doesn't exist in the object) console.log("address" in Data); Outputtrue falseJavaScript instanceof OperatorThe instanceof operator in JavaScript tests if an object is an instance of a particular class or constructor, returning a Boolean value. JavaScript let languages = ["HTML", "CSS", "JavaScript"]; console.log(languages instanceof Array); console.log(languages instanceof Object); console.log(languages instanceof String); console.log(languages instanceof Number); Outputtrue true false false JavaScript let myString = new String(); let myDate = new Date(); console.log(myString instanceof Object); console.log(myString instanceof Date); console.log(myString instanceof String); console.log(myDate instanceof Date); console.log(myDate instanceof Object); console.log(myDate instanceof String); Outputtrue false true true true false Comment More infoAdvertise with us Next Article JavaScript String Operators V vishalkumar2204 Follow Improve Article Tags : JavaScript Web Technologies javascript-operators Similar Reads JavaScript Tutorial JavaScript is a programming language used to create dynamic content for websites. It is a lightweight, cross-platform, and single-threaded programming language. 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JavaScript// Illustration of (==) operator let x = 5; let y = '5'; // Checking of operands c 5 min read JavaScript Logical OperatorsLogical operators in JavaScript are used to perform logical operations on values and return either true or false. These operators are commonly used in decision-making statements like if or while loops to control the flow of execution based on conditions.In JavaScript, there are basically three types 5 min read JavaScript Bitwise OperatorsIn JavaScript, a number is stored as a 64-bit floating-point number but bitwise operations are performed on a 32-bit binary number. To perform a bit-operation, JavaScript converts the number into a 32-bit binary number (signed) and performs the operation and converts back the result to a 64-bit numb 5 min read JavaScript Ternary OperatorThe Ternary Operator in JavaScript is a shortcut for writing simple if-else statements. It’s also known as the Conditional Operator because it works based on a condition. The ternary operator allows you to quickly decide between two values depending on whether a condition is true or false.Syntax:con 5 min read JavaScript Comma OperatorJavaScript Comma Operator mainly evaluates its operands from left to right sequentially and returns the value of the rightmost operand. JavaScriptlet x = (1, 2, 3); console.log(x); Output3 Here is another example to show that all expressions are actually executed.JavaScriptlet a = 1, b = 2, c = 3; l 2 min read JavaScript Unary OperatorsJavaScript Unary Operators work on a single operand and perform various operations, like incrementing/decrementing, evaluating data type, negation of a value, etc.Unary Plus (+) OperatorThe unary plus (+) converts an operand into a number, if possible. It is commonly used to ensure numerical operati 4 min read JavaScript in and instanceof operatorsJavaScript Relational Operators are used to compare their operands and determine the relationship between them. They return a Boolean value (true or false) based on the comparison result.JavaScript in OperatorThe in-operator in JavaScript checks if a specified property exists in an object or if an e 3 min read JavaScript String OperatorsJavaScript String Operators are used to manipulate and perform operations on strings. There are two operators which are used to modify strings in JavaScript. These operators help us to join one string to another string.1. Concatenate OperatorConcatenate Operator in JavaScript combines strings using 3 min read JS StatementsJavaScript StatementsJavaScript statements are programming instructions that a computer executes. A computer program is essentially a list of these "instructions" designed to perform tasks. In a programming language, such instructions are called statements.Types of Statements1. Variable Declarations (var, let, const)In 4 min read JavaScript if-elseJavaScript if-else statement executes a block of code based on a condition. 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