What is a Pure Function in JavaScript?

A function is considered pure if it has the following characteristics:
The function always produces the same output given the same input
The function doesn’t modify the state of the application
The function doesn’t make any side-effects, like calling API’s, writing to the screen, etc

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What is a function?

In JavaScript, a function is a first-class object, which means that it can be treated like any other object in the language. Functions can be created and used in many different ways, but one of the most common and important uses for functions is to create what are known as pure functions.

A pure function is a function that always returns the same result for the same input and has no side effects. In other words, a pure function is a function that only does what it is supposed to do and nothing more.

For example, consider the following two functions:

function add(a, b) {
return a + b; // This function is pure
}

function printAndAdd(a, b) {
console.log(a + b); // This function is not pure because it has a side effect (it prints to the console)
return a + b; // This function is still considered pure because it always returns the same result for the same input. However, it would be more accurate to say that it is impure because of its side effect.
}

What is a pure function?

In JavaScript, a “pure function” is a function that:

– doesn’t modify any of the arguments it receives
– only depends on its arguments and doesn’t access any global state (i.e. variables defined outside of the function)
– always returns the same result given the same arguments

What are the benefits of pure functions?

There are a few benefits that come from using pure functions in your code:

-They are more predictable and easier to reason about
-They are easier to test
-They are easier to parallelize and scale

What are the characteristics of pure functions?

In JavaScript, a function is considered pure if it:

– Is idempotent (produces the same results given the same inputs)
– Does not change any external state (variables, data structures, etc.)
– Does not use any impure functions
A function that meets all three of these criteria is referred to as a ” referentially transparent ” function.

How can you create pure functions in JavaScript?

In JavaScript, a function is considered pure if it has the following characteristics:

-It always returns the same output for the same input.
-It doesn’t rely on any external state or data.
-It doesn’t mutate any external state or data.

To put it another way, a pure function is one that given the same input will always return the same output, and that doesn’t have any side effects. Pure functions are a fundamental concept in functional programming.

There are a few ways to create pure functions in JavaScript. One way is to use Function.prototype.bind():

var pureFunction = function(arg1, arg2) {
return arg1 + arg2;
}.bind(this);

Another way is to use an arrow function:

var pureFunction = (arg1, arg2) => arg1 + arg2;

What are some examples of pure functions in JavaScript?

In JavaScript, a function is considered pure if it has the following characteristics:

– It does not modify any of the arguments that are passed to it
– It does not rely on any side effects or external state (this includes variables declared outside of the function)
– It always returns the same result when given the same arguments

Here are some examples of pure functions in JavaScript:

function add(a, b) {
return a + b;
}

function isPositive(num) {
return num >= 0;
}

function square(x) {
return x * x;
}