JavaScript Interview questions

In JavaScript, event bubbling is a mechanism that describes the way events propagate up through the DOM hierarchy. When an event is triggered on an element, it first triggers on that element and then "bubbles up" through all its ancestor elements. For example, if you click on a

In JavaScript, a closure is created when a function is defined inside another function. The inner function has access to the outer function's variables and parameters, even after the outer function has returned. This happens because the inner function "closes over" the variables and parameters of

Hoisting is a behavior in JavaScript where variable declarations and function declarations are moved to the top of their respective scopes during the compilation phase, before the code is executed. This means that variables and functions can be used before they are declared in the code. For example, if you

In JavaScript, there are three ways to declare a variable: using the "var", "let", and "const" keywords. Each of these keywords has slightly different behavior and scoping rules: "var": This keyword was used in older versions of JavaScript and is still supported

In JavaScript, null and undefined are both used to represent the absence of a value, but they have slightly different meanings. Undefined is a value automatically assigned to a variable that has been declared but has not been initialized with a value, or to a function parameter that has not

In JavaScript, you can declare boolean values using the "boolean" data type, which can have only two possible values: true or false. Here are some examples: // Declaration of boolean values let isTrue = true; let isFalse = false; // Boolean operations let result1 = isTrue && isFalse; // logical AND let result2