As we know there is a .forEach() method for arrays in JavaScript. But Strings don't have that method built in.

So, is there any issue regarding the following code snippet: String.prototype.forEach = Array.prototype.forEach ?

This setting helps me to use .forEach for Strings.

let myName = "Avetik";   

String.prototype.forEach = Array.prototype.forEach;

myName.forEach(char => {

console.log(char);
})

The above code works fine and outputs all chars of my name.

You already guessed that I am a newbie in JS.

CodePudding user response：

You can, but:

• it's confusing (other developers working on the same codebase could well be very confused at seing such a method called on a string)
• can lead to fragile code (if you define String.prototype.forEach, it may interfere with other code that uses methods on the String prototype)
• doesn't help much: you can do [...str].forEach very easily, and you can also do for (const char of str) { very easily

Show code snippet

// Say we want to iterate over this string:
const str = 'str';

// without adding a method to the prototype. Easy:

// One method:
for (const char of str) {
  console.log(char);
}

// Another method:
[...str].forEach((char) => {
  console.log(char);
});

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• can damage the future syntax of the language if enough script-writers define such a thing (see what happened with Array.prototype.contains and Array.prototype.flatten)

So, it's doable, but it's probably not a good idea.

CodePudding user response：

You can add your own wrapper...

I can hardly resist such bad ideas!
My advice, do it, and wait for the day or such practices will turn against you dearly. Then you will have the measure of such an error, which I hope will definitely dissuade you from playing with language syntax, and with any luck you might be able to become a computer language guru.

if(typeof String.prototype.forEach !== "function") {
  String.prototype.forEach = Array.from(this).forEach
};

// sample usage :
let abc = 'abc'

abc.forEach((letter, index)=> console.log(letter,index))

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but it would be better to use a less ambiguous name

if(typeof String.prototype.forEachLetter !== "function") {
  String.prototype.forEachLetter = Array.from(this).forEach
};

// sample usage :
let abc = 'abc'

abc.forEachLetter((letter, index)=> console.log(letter,index))

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CodePudding user response：

.forEach() is inherently a function for arrays (groups of multiple things). A string is just 1 thing, there's no way to do something for "each" when there's only 1.

You can use .split() on a string to turn it into an array of every character. Then do whatever array operations you want on the result of that. And then .join() on the array to turn it back into a string if you need to.

var myString = "beans";
var myArray = myString.split(); // this will be an array of 5 strings: ['b', 'e', 'a', 'n', 's']