Prototype Alternative in Javascript

Question

How can i replace prototype and make the same code below to work? in other words i wanna write a code with the same meaning/logic without using prototype.

String.prototype.replaceAt = function(index, character) {
    return this.substr(0, index) + character + 
        this.substr(index + character.length);              
}

Mr.Ahmed i tried to implement your method, but it's not working for some reason. is it possible to make a separate function that can do the same job. my only problem is, i cant show all my project publicly. is it possible to communicate with u privately? — user2995331
– user2995331, Commented Nov 23, 2013 at 7:09
Can you show me how you are defining and using it? There might be something wrong there...... — MD Sayem Ahmed
– MD Sayem Ahmed, Commented Nov 23, 2013 at 9:53
am using it for a spellchecker program. in-line function to replace character in a string. — user2995331
– user2995331, Commented Nov 23, 2013 at 16:45

MD Sayem Ahmed · Accepted Answer · 2013-11-23 04:47:30Z

1

Create it as a method of a custom utility object -

var StringUtils = {};

StringUtils.replaceAt = function (str, index, character) {
    return str.substr(0, index) + character + 
        str.substr(index + character.length);
}

and then call it like this -

var str = "Hello";
StringUtils.replaceAt(str, 0, "A");

answered Nov 23, 2013 at 4:47

MD Sayem Ahmed

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Comments

Ben · Accepted Answer · 2013-11-23 05:19:48Z

0

You can just define it as a function and use the call or apply prototype method

replaceAt = function(index, character) {
  return this.substr(0, index) + character + this.substr(index+character.length);
}

How to use?

var str = "Javascript is Awesome";
replaceAt.call(str, 0, "A");
// or 
replaceAt.apply(str, [0, "A"]);

answered Nov 23, 2013 at 5:19

Ben

1413 bronze badges

2 Comments

MD Sayem Ahmed Over a year ago

You see, it's not a good idea to force the use of apply/call by using this inside the function. It's not intuitive and hence can create hard-to-find bugs.

Ben Over a year ago

@SayemAhmed True, I was not sure how extreme the questioner was about "same meaning/logic". Your method is how I would probably do it.

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