# What is a mistake i made in this code?

**URL:** <https://forum.kirupa.com/t/what-is-a-mistake-i-made-in-this-code/650363>\
**Category:** web dev\
**Created:** [January 7, 2022, 10:15am UTC](https://forum.kirupa.com/t/what-is-a-mistake-i-made-in-this-code/650363 "2022-01-07T10:15:34Z")\
**Posts on this page:** 5\
**Page:** 1

<div class="post-metadata">

**Author:** ![Programmer\_Uz](https://yyz1.discourse-cdn.com/flex011/user_avatar/forum.kirupa.com/programmer_uz/32/16357_2.png) [@Programmer\_Uz](https://forum.kirupa.com/u/Programmer_Uz)\
**Post date:** [January 7, 2022, 10:15am UTC](https://forum.kirupa.com/t/what-is-a-mistake-i-made-in-this-code/650363/1 "2022-01-07T10:15:34Z")

</div>

Hi Kirupa! What is a mistake i made in this code? Where is my mistake? I think, I did all correct, but I can’t see result. I want to do cards as cards in online-shops

```auto
class Btn extends React.Component {

            render(){

                var btnObject = {

                    padding:10,

                    boxSizing:'border-box',

                    backgroundColor: '#006400',

                    borderRadius:10,

                    border:'none',

                    color:'white'

                }

                return (

                    <button style = {btnObject}>Click me</button>

                )

            }

        }

        class Card extends React.Component {

            render(){

                var cardObject = {

                    backgroundColor:'white',

                    height:200,

                    width:150,

                    borderRadius:10,

                }

                return(

                    <div style = {cardObject}>

                        <topCard/>

                    </div>

                )

            }

        }

        class topCard extends React.Component{

            render(){

                var CardTop = {

                    height:150,

                    backgroundColor:'#DC143C'

                }

                return(

                    <div style = {CardTop}></div>

                )

            }

        }

        ReactDOM.render(

            <div class = 'dflex'>

                <Card/>

                <Card/>

                <Card/>

                <Card/>

            </div>,

            document.querySelector('#container')

        )

```

---

<div class="post-metadata">

**Author:** ![kirupa](https://yyz1.discourse-cdn.com/flex011/user_avatar/forum.kirupa.com/kirupa/32/11616_2.png) [@kirupa](https://forum.kirupa.com/u/kirupa)\
**Post date:** [January 7, 2022, 7:59pm UTC](https://forum.kirupa.com/t/what-is-a-mistake-i-made-in-this-code/650363/2 "2022-01-07T19:59:31Z")

</div>

What is the error you see in the console?

---

<div class="post-metadata">

**Author:** ![senocular](https://yyz1.discourse-cdn.com/flex011/user_avatar/forum.kirupa.com/senocular/32/7217_2.png) [@senocular](https://forum.kirupa.com/u/senocular)\
**Post date:** [January 7, 2022, 11:33pm UTC](https://forum.kirupa.com/t/what-is-a-mistake-i-made-in-this-code/650363/3 "2022-01-07T23:33:58Z")

</div>

You should capitalize topCard.

```
topCard -> TopCard
```

---

<div class="post-metadata">

**Author:** ![Programmer\_Uz](https://yyz1.discourse-cdn.com/flex011/user_avatar/forum.kirupa.com/programmer_uz/32/16357_2.png) [@Programmer\_Uz](https://forum.kirupa.com/u/Programmer_Uz)\
**Post date:** [January 8, 2022, 4:56pm UTC](https://forum.kirupa.com/t/what-is-a-mistake-i-made-in-this-code/650363/4 "2022-01-08T16:56:31Z")

</div>

Thanks very much, your advice helped me!!!

---

<div class="post-metadata">

**Author:** ![Programmer\_Uz](https://yyz1.discourse-cdn.com/flex011/user_avatar/forum.kirupa.com/programmer_uz/32/16357_2.png) [@Programmer\_Uz](https://forum.kirupa.com/u/Programmer_Uz)\
**Post date:** [January 8, 2022, 4:57pm UTC](https://forum.kirupa.com/t/what-is-a-mistake-i-made-in-this-code/650363/5 "2022-01-08T16:57:12Z")

</div>

I should capitalize topCard, I found my mistake, thanks for feedback