A function in JS with parameter passing

Question

It's the test task on the job.

A farmer has rabbits. Each rabbit is its weight. When the time comes, he kills them function cut(rabbit). You must write a function of cut so that it had the appearance of cut(rabbit1)(rabbit2)...(rabbitN) and deduced the total mass and the number of rabbits.

For example:

var rabbit1 = {weight: 5},
    rabbit2 = {weight: 4};

console.log(cut(rabbit1)(rabbit2));

In the console we will see "9 kg of rabbits or 2 pieces".

JSFiddle - https://jsfiddle.net/sjao7ut8/

How I can write function cut()?

@BlazeSahlzen I don't know how I can pass parameters in function like this. — Luntegg
– Luntegg, Commented Jun 6, 2016 at 9:06
If you need more than one parameter (rabbit1, ...., rabbitn), you just pass all the rabbits you want. Javascript functions don't care — Thor Jacobsen
– Thor Jacobsen, Commented Jun 6, 2016 at 9:08
why dont you use array rabbits instead of rabbit1, rabbit2, and so on ? and also show us what you've done so far. — Jairo Malanay
– Jairo Malanay, Commented Jun 6, 2016 at 9:08
You need to research function currying. I wouldn't be surprised if you need to have an empty set of parentheses at the end too, ie console.log(cut(rabbit1)(rabbit2)()); — James Thorpe
– James Thorpe, Commented Jun 6, 2016 at 9:08
If I understand the words "test task on the job" correctly, you have applied for a job which obviously wants you to have a certain level of javascript skills. And then you say you "don't know how you can pass parameters in function like this"? — devnull69
– devnull69, Commented Jun 6, 2016 at 9:12

Nina Scholz · Accepted Answer · 2016-06-06 09:19:16Z

7

You could use chaining, a fluent interface, which returns the function you called until the environment requires a primitive value.

function cut(rabbit) {
    var weight = 0,
        count = 0,
        fn = function (o) {
            weight += o.weight;
            count++;
            return fn;
        };

    fn.toString = function () {
        return weight + ' kg of rabbits or ' + count + ' piece' + (count > 1 ? 's' : '');
    }

    return fn(rabbit);
}

var rabbit1 = { weight: 5 },
    rabbit2 = { weight: 4 };
    
console.log(cut(rabbit1)(rabbit2));

edited Jun 6, 2016 at 9:19

answered Jun 6, 2016 at 9:16

Nina Scholz

388k26 gold badges367 silver badges417 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

Soubhik Mondal Over a year ago

In the chrome dev console this prints and extra function before the output. Can anything be done about that?

Nina Scholz Over a year ago

@BlazeSahlzen, you can prepend an empty string, like console.log('' + cut(rabbit1)(rabbit2));

Nina Scholz Over a year ago

@JustusRomijn, yes, because the function is retuned

pwolaq · Accepted Answer · 2016-06-06 09:15:47Z

0

what you need to do here is to use recursive call, which returns a function and uses arguments.callee

something like this should do the job:

function cut(firstRabbit) {
    var mass = firstRabbit.weight;
    return function(nextRabbit) {
        if (typeof nextRabbit !== 'undefined') {
            mass += nextRabbit.weight;
            return arguments.callee;
        } else {
            return mass;
        }
    };
}

Example usage (remember to add () at the end):

var rabbit1 = {weight: 5},
rabbit2 = {weight: 4};

console.log(cut(rabbit1)(rabbit2)());

edited Jun 6, 2016 at 9:15

answered Jun 6, 2016 at 9:10

pwolaq

6,41221 silver badges45 bronze badges

Comments

Oshadha · Accepted Answer · 2016-06-06 10:55:08Z

0

You can try following code:

var farmer = { 
    cut: function(rabits) { 
    var cutWeight = 10;
    var totalCuts = 0;
    var totalWeight = 0;
    var count = rabits.length;

    for(var i=0; i < count; i++) {
        var rabit = rabits[i];

      if(rabit.weight >= cutWeight) {
        totalWeight += rabit.weight;
        if(totalCuts === 0) {
            totalCuts = 1;
        }
        else {
            totalCuts += 1;
        }
      }
    }

    console.log(totalWeight + "Kg of Rabits and " + totalCuts + "cuts.")
  }
};

farmer.cut([{weight: 11}, {weight: 5}, {weight: 13}]); // Call the function

Hope this will help you.

answered Jun 6, 2016 at 10:55

Oshadha

54810 silver badges25 bronze badges

Comments

Ivan Pomortsev · Accepted Answer · 2016-06-06 09:33:34Z

-1

Function.prototype.toString = function() {
 return Function.prototype.rabbitsWeight + "кг кроликов или " + Function.prototype.rabbitsCount + " штук";
}; 

Function.prototype.rabbitsWeight = 0;
Function.prototype.rabbitsCount = 0;

window.rabbitsCut = eval("new Function('rabbit', 'Function.prototype.rabbitsWeight += rabbit.weight; ++Function.prototype.rabbitsCount; return eval(window.rabbitsCut);');");

var cut = window.rabbitsCut;

console.log(cut({weight: 5})({weight: 4}));

answered Jun 6, 2016 at 9:33

Ivan Pomortsev

2482 silver badges10 bronze badges

Collectives™ on Stack Overflow

A function in JS with parameter passing

4 Answers 4

3 Comments

Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

4 Answers 4

3 Comments

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related