Introduction to JavaScripteval () function and application example _ javascript skills

The eval (String) function can calculate a String and execute the JavaScript code. This method only accepts the original String as the eval (String) parameter to calculate a String, and execute the JavaScript code.

Return Value

Returns the string value (if any ).

Description

This method only accepts the original string as the parameter. If the string parameter is not the original string, this method will be returned without any change. Therefore, do not pass a String object as a parameter for the eval () function.

If you try to override the eval attribute or assign the eval () method to another attribute and call it through this attribute, ECMAScript can throw an EvalError exception.

Throw

If the parameter does not contain valid expressions and statements, a SyntaxError exception is thrown.

If eval () is illegally called, an EvalError error is thrown.

If the Javascript code passed to eval () generates an exception, eval () will pass the exception to the caller.

Tips and comments

Tip: Although eval () is very powerful, it is rarely used in actual use.

Example: