JAVASCRIPT

check if a class exists javascript

const element = document.querySelector("#box");

element.classList.contains("active");

check if body has class javascript

document.body.classList.contains('my-class-name')

how to check has class name in js?

        
            
        
     element.classList.contains(className);Code language: CSS (css)

check if value is a class nodejs

export const isClass = <T>(value: unknown): value is Constructor<T> => {
	return typeof value === "function" && typeof value.prototype === "object";
};

export type Constructor<T> = new (...args: unknown[]) => T;