Can String-Based Function Calls with setTimeout Be Justified?

Passing a String to setTimeout: Reasons for Avoidance and the Exception

Passing a string to setTimeout or its setInterval counterpart is generally frowned upon devido a concerns of executing in the global scope, potential performance issues, and security vulnerabilities. The recommended alternative is to use an anonymous function as the first argument.

However, there may be a saving grace in certain situations. If the programmer intends to access a function or variable that exists in the global scope but has been overridden locally, they may consider using the deprecated string syntax. Nevertheless, this approach is deemed poor programming practice due to the potential for variable shadowing.

In most cases, it is possible to access global variables as properties of the window object (e.g., window.globalVar), making it unnecessary to resort to string-based function calls. Therefore, it is highly unlikely to encounter a scenario where using a string as the first argument for setTimeout or setInterval would be genuinely beneficial.

Historically, the sole availability of a code string as an argument for these functions stemmed from JavaScript 1.0's limitations. The introduction of a Function object reference as an argument only occurred with JavaScript 1.2. Maintaining compatibility with older browsers and scripts prevents developers from completely eliminating string-based calls. By understanding both the caveats and the rare exception, programmers can make informed decisions when writing code involving setTimeout and setInterval.

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