JavaScript Functions Deep Dive

A function can also create with new keyword. And a function can assigning with multiple ways. And It’s called the Function Constructor. Function this is our function Constructor.

⇒ Simple Function..

// Function define & defination..
function strToObj(str){
    let obj = new Object();

    for (let s of str){
        if (s !== ''){
            obj[s] = s;
        }
    }
    return obj;
}

// Invoking function with calling..
console.log(strToObj("Asad Anik"));

⇒ Construct a function. This mode is awesome to working and declaring function inside the Runtime😎. And the Runtime makes it the normal function as well. This also known as Runtime Function.

→ Similar function with new keyword like creating an Object or calling Class’s Constructor method.

→ Syntax ⇒ new Function(Arguments, Body);

// Actual function in JavaScript Behid the scense..
const strToObj = new Function(
    'str',
    `let obj = new Object();

    for (let s of str){
        if (s !== ''){
            obj[s] = s
        }
    }
    return obj;`
);

console.log(strToObj("Asad Anik"));

→ With multiple params.

⇒ Syntax — new Function(Argument1, Argument2, ….., Body);

// Multiple arguments..
const mySum = new Function(
    'a',
    'b',
    `
        const sum = a + b;
        console.log(sum);
    `
);

// Calling & Invoking..
mySum(20, 10);

→ Also can code like this way.

// Take all data of function into an object.
const fData = {
    params: ['num1', 'num2'],
    body: ['const sum = num1 + num2', 'return sum']
};

// Bring body array to string body..
const fBody = fData.body.reduce((acc, cur) => {
    acc += cur + ';';
    return acc;
}, '');

// Calling Function Constructor..
const myOwnFunc = new Function(...fData.params, fBody);
console.log(myOwnFunc(20, 10));

Multiple Operations Constructor Function.

// Mutiple Operations Constructor Function..
const Operations = [
    {
        args: [10, 20],
        params: ['num1', 'num2'],
        body: `console.log("Operation 1:", num1 + num2)`
    },
    {
        args: [10, 20],
        params: ['num1', 'num2'],
        body: `console.log("Operation 2:", num1 - num2)`
    },
    {
        args: [10, 20],
        params: ['num1', 'num2'],
        body: `console.log("Operation 3:", num1 * num2)`
    },
    {
        args: [10, 20],
        params: ['num1', 'num2'],
        body: `console.log("Operation 4:", num1 / num2)`
    },
];

// Calling Stack..
Operations.forEach((operation) => {
    const fn = new Function(...operation.params, operation.body);
    fn(...operation.args);
});