What is the process for evaluating the variable `results` in this scenario?

Question

What is the process for evaluating the variable `results` in this scenario?

Can anyone provide some insight on how this code is functioning?

I grasp the concept of callbacks but during a tutorial video, I encountered this code snippet:

function addAndHandle(n1, n2, cb) {
    const result = n1 + n2;
    cb(result);
}

addAndHandle(10, 20, function (results) {
    console.log(results);
});

My question pertains to how results is calculated within the callback. Initially, the result is passed into the callback in the function declaration which seems logical as the sum is stored in result. However, later on, I utilize results, so how does it display the sum of 10 and 20 or any other values assigned to n1 and n2?

javascript

Answer 1

Answer №1

When the function is called, it takes in three parameters.

The values of n1 and n2 are added together within the function and stored in a variable.

This result is then passed to another function as an argument.

You may find it helpful to use different parameter names for clarity.

function addAndHandle(n1, n2, callback) {
    const sum = n1 + n2;
    callback(sum);
}

addAndHandle(10, 20, function (result) {
    console.log(result);
});

Answer 2

When the function is called, it takes in three parameters.

The values of n1 and n2 are added together within the function and stored in a variable.

This result is then passed to another function as an argument.

You may find it helpful to use different parameter names for clarity.

function addAndHandle(n1, n2, callback) {
    const sum = n1 + n2;
    callback(sum);
}

addAndHandle(10, 20, function (result) {
    console.log(result);
});

Answer 3

Answer №2

Perhaps presenting it in this format will aid your comprehension:

function performOperation(num1, num2, callback) {
    const result = num1 + num2;
    callback(result);
}

function displayOutput(output) {
    console.log(output);
}

performOperation(10, 20, displayOutput);

Within the performOperation function, you execute the callback - in this case, calling displayOutput with a result of 30. This is equivalent to invoking displayOutput with 30:

displayOutput(30)

Therefore, the output is calculated utilizing const result = num1 + num2, which is then passed to the displayOutput function.

In your illustration, an anonymous function is utilized as the callback, but the underlying logic remains consistent. I simply separated your original callback into a distinct function for simplification purposes.

Answer 4

Perhaps presenting it in this format will aid your comprehension:

function performOperation(num1, num2, callback) {
    const result = num1 + num2;
    callback(result);
}

function displayOutput(output) {
    console.log(output);
}

performOperation(10, 20, displayOutput);

Within the performOperation function, you execute the callback - in this case, calling displayOutput with a result of 30. This is equivalent to invoking displayOutput with 30:

displayOutput(30)

Therefore, the output is calculated utilizing const result = num1 + num2, which is then passed to the displayOutput function.

In your illustration, an anonymous function is utilized as the callback, but the underlying logic remains consistent. I simply separated your original callback into a distinct function for simplification purposes.

Answer 5

Answer №3

It seems there may be some confusion as result and results are essentially the same in this particular scenario. Your result is passed into your callback function (

function (results) {console.log(results);}

) as results

These are the values you are working with towards the end

function addAndHandle(n1 /* 10 */, n2 /* 20 */, cb /* function (results) {console.log(results);} */) {
    const result = n1 + n2; /* 30 */
    // This line simply invokes your callback function below with the value of result, which is 30
    cb(result /* 30 */);

    // If you are familiar with IIF
    (function (results) {console.log(results);})(result);


addAndHandle(10, 20, function (results /* 30 */) {
    console.log(results /* 30 */);
});

Answer 6

It seems there may be some confusion as result and results are essentially the same in this particular scenario. Your result is passed into your callback function (

function (results) {console.log(results);}

) as results

These are the values you are working with towards the end

function addAndHandle(n1 /* 10 */, n2 /* 20 */, cb /* function (results) {console.log(results);} */) {
    const result = n1 + n2; /* 30 */
    // This line simply invokes your callback function below with the value of result, which is 30
    cb(result /* 30 */);

    // If you are familiar with IIF
    (function (results) {console.log(results);})(result);


addAndHandle(10, 20, function (results /* 30 */) {
    console.log(results /* 30 */);
});

What is the process for evaluating the variable `results` in this scenario?

Answer №1

Answer №2

Answer №3

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