Javascript:Currying

Currying is a transformation of functions that translates a function

from callable as f(a, b, c) into callable as f(a)(b)(c).

consider simple add function

//normal function

function Add(a,b)

{

return a+b;

}

lets convert into to currying:

Code:

function AddByCurring(a) {

return function (b) {

return a + b;

};

}

let result = AddByCurring(5)(6);

console.log(result);

Output:

11

Consider another code snippet below

Code:

//currying in javascript

let data = [

{ name: "sangram", email: "sangram@gmail.com" },

{ name: "saurabh", email: "saurabh@gmail.com" },

];

function Filter(key) {

return function (object) {

return object[key];

};

}

let funcGetName = Filter("name");

let nameResult = data.map(funcGetName);

console.log(nameResult);

let funcGetEmail = Filter("email");

let emailResult = data.map(funcGetEmail);

console.log(emailResult);

Output:

[ 'sangram', 'saurabh' ]

[ 'sangram@gmail.com', 'saurabh@gmail.com' ]

Another example of currying:

function Avg(...n)

{

return function cncat(...m)

{

n = n.concat(m)

let sum =0

for(let i=0;i < n.length;i++)

{

sum = sum + n[i]

}

return sum/n.length;

}

}

let avgVal = Avg(5,11)

let an = avgVal(8,8)

console.log("AVG:" + an);

Output:

AVG:8