Why is .toUpperCase() not working?

Question

I am very new with framer.js and I am just following a book called http://coffeescript-for-framerjs.com/#buy where it's written

fruits[1].toUpperCase() It was working properly

fruits.toUpperCase()

Here in book it's fruit not fruits i tried both but getting error

Now i got it that toUpperCase() is a string method so it will not work with Array. but what exactly book is saying here then.

As `fruits` is an array and it doesn't have the method. `toUpperCase()` is string method. So error is correct, Use a simple for loop — Satpal, May 09 '15 at 09:08

score 8 · Answer 1 · edited Dec 29 '15 at 14:59

8

Why:

.toUpperCase() is a method of the String.prototype, not the Array.prototype.

An example of the correct syntax in your case:

var fruits = ['apple', 'orange', 'kiwi']

for (var i = 0; i < fruits.length; i++) {
    fruits[i] = fruits[i].toUpperCase();
}

edited Dec 29 '15 at 14:59

Praveen Kumar Purushothaman

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answered May 09 '15 at 09:20

b00t

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score 1 · Answer 2 · answered May 09 '15 at 09:08

1

Fruits is an array. toUpperCase function is not defined on array but for string objects.

answered May 09 '15 at 09:08

V31

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score 1 · Answer 3 · answered May 09 '15 at 09:09

1

Because fruits[1] referring to your array element which is of type String

toUpperCase() can only be used for String type.

fruits.toUpperCase() is failing fruits is of type Array

Read More here

answered May 09 '15 at 09:09

Sunil B N

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score 1 · Answer 4 · answered May 09 '15 at 09:58

If you want to make it work that way:

Array.prototype.toUpperCase = function() {
    for(var i = 0; i < this.length; i++)
        if(typeof this[i] === 'string')
            this[i] = this[i].toUpperCase();
}

To test:

var fruits = ["oranges", "apples", "bananas"];
fruits.toUpperCase();
console.log(fruits.toString());

ORANGES,APPLES,BANANAS

score 0 · Answer 5 · edited Dec 17 '20 at 08:02

0

I was also able to solve it with the below:

let fruit = new Array("peach","orange", "mango", "apple" );
console.log(fruit.toString().toUpperCase());

edited Dec 17 '20 at 08:02

mr NAE

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answered Dec 17 '20 at 04:26

nabdevtech

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@MakwanaPrahlad sure! So the other answers called the array to a string in one line and then called the string to all Uppercase in the next line. I opted to join them together in one line to show I was calling this array to a string to make it uppercase. I am new to coding so I don't know if condensing it this way is best practice, but it did work for me and saved an extra step – nabdevtech Dec 17 '20 at 19:57

Why is .toUpperCase() not working?

5 Answers5