Get all the methods of an object using JavaScript

Last Updated : 14 Oct, 2025

In JavaScript, you can retrieve all the methods of an object by inspecting its properties and checking which ones are functions. This is useful for debugging or dynamically analysing objects.

[Approach 1]: Use typeof operator and filter() Methods

  • Create a function that takes an object as input.
  • Use typeof operator, which checks if the type of object is a function or not.
  • If the type of object is a function then it returns the object.
JavaScript 
function Obj() {
    this.m1 = function M1() {
        return "From M1";
    }
    this.m2 = function M2() {
        return "From M2";
    }
}

function getAllMethods(obj = this) {
    return Object.keys(obj)
        .filter((key) => typeof obj[key] === 'function')
        .map((key) => obj[key]);
}

function print() {
   console.log(getAllMethods(new Obj()));
}
print();

Output
[ [Function: M1], [Function: M2] ]

[Approach 2]: Use typeof operator and for-in loop

Use the for-in loop to iterate over all properties of an object and check each one with the typeof operator to identify methods.

  • Create a function that takes an object as input.
  • Usetypeof operator, which checks if the type of object is a function or not. This example also checks if any error occurred or not and if occurred then handle it properly.
  • If the type of Object is a function then return it.
JavaScript 
function Obj() {
    this.m1 = function M1() {
        return "From M1";
    }
    this.m2 = function M2() {
        return "From M2";
    }
}

function getAllMethods(obj) {
    let result = [];
    for (let id in obj) {
        try {
            if (typeof (obj[id]) == "function") {
                result.push(id + ": " + obj[id].toString());
            }
        } catch (err) {
            result.push(id + ": Not accessible");
        }
    }
    return result;
}

function print() {
   console.log(getAllMethods(new Obj()).join("\n"));
}
print();

Output
m1: function M1() {
        return "From M1";
    }
m2: function M2() {
        return "From M2";
    }
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