isFunction

Using

This function determines whether the given value is a real function.

• Returns true for standard functions, arrow functions, async, generator, class constructors, built-ins, and Function instances.
• Returns false for all non-function values, including objects with .call, arrays, primitives, and browser-specific quirks like document.all.

Arguments

Argument	Type	Description	Example
value	unknown	Can be any type	"text" 2 undefined

Returns

boolean — true if value is a function, false otherwise

Examples

isFunction(() => {});
// true

isFunction(async function () {});
// true

isFunction(class {});
// true

isFunction({ call: () => {} });
// false

isFunction(null);
// false

isFunction(() => () => {});
// true

isFunction('function');
// false

Resources

📦 Since:1.3.0

📦 Last updated:1.3.0

📦 Available in:1.3.0

Source codeCode sandbox