When invoking a function like func.apply() versus func.call(), how do these two differ in handling arguments? Are there any performance differences between them, and when should you prefer using call over apply or vice versa?
I’ve been working with JavaScript for over a decade now, and one thing that still confuses many devs early on is the difference between call and apply. At their core, both let you invoke a function and set its this context — super useful for borrowing methods or controlling context.
Now, here’s the key difference in the javascript apply vs.call discussion:
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calltakes arguments one by one:func.call(thisArg, arg1, arg2, ...) -
applytakes arguments as an array:func.apply(thisArg, [arg1, arg2, ...])
So if you already have your arguments in an array, apply just saves you that little extra step.
Use call when you know the exact number of arguments and want to pass them directly. Use apply when your arguments are dynamic or come as an array. Performance-wise, in modern engines, the difference is usually negligible — just pick the one that matches your use case better. For example, apply is useful for spreading arrays before ES6 spread syntax became common.
Yep, nailed it, @shilpa.chandel. Having spent time maintaining both modern and legacy codebases, I’d add that with ES6 giving us the spread operator, the javascript apply vs.call debate has softened a bit. You can now do everything apply did using call with spread syntax, like func.call(thisArg, ...argsArray).
So today, developers tend to lean toward call because it reads more cleanly and aligns better with modern syntax practices. But apply still has its place — especially in legacy code or when you’re unsure whether all environments support spread. In real-world use, I mostly pick the one that fits the data structure I’m working with. At this point, it’s really about readability and intent more than performance.