The eval() function in JavaScript is used to evaluate a string of code as if it were part of the current program. It is a global function in JavaScript that evaluates the specified string as JavaScript code and executes it. If the parameter of eval() is an expression, it evaluates the expression. If the parameter is one or more JavaScript statements, eval() executes the statements. The function returns the completion value of evaluating the given code. If the completion value is empty, undefined is returned. If the script is not a string primitive, eval() returns the argument unchanged.
However, using eval() is generally considered bad practice because it is an enormous security risk. It is too easy for a bad actor to run arbitrary code when eval() is used. With eval(), malicious code can run inside an application without permission, and third-party code can see the scope of an application, which can lead to possible attacks. Therefore, it is not recommended to use eval() because it is slower and makes code unreadable. Instead of using eval(), it is better to use code or a function.
In summary, eval() is a function in JavaScript that evaluates a string of code as if it were part of the current program. However, it is generally considered bad practice to use eval() because it is an enormous security risk and can make code unreadable and slower.
