Mapping through an object with arrays in React

Question

I would like to map through the array, so inside one of the column there would be only 3 items. So first there would be 3 items inside of the column, and then it would map through another column. Should I double map it somehow?

So it would be: Column div => 3 items maps inside => Column div

Data:

const files = {
    columnOne: [
      {
        item: {
          className: X,
          icon: X,
          typographyHeader: X,
          typographyDeemphasized: X,
        },
      },
      {
         item: {
          className: X,
          icon: X,
          typographyHeader: X,
          typographyDeemphasized: X,
        },
      },
      {
         item: {
          className: X,
          icon: X,
          typographyHeader: X,
          typographyDeemphasized: X,
        },
      },
    ],
    columnTwo: [
      {
         item: {
          className: X,
          icon: X,
          typographyHeader: X,
          typographyDeemphasized: X,
        },
      },
      {
         item: {
          className: X,
          icon: X,
          typographyHeader: X,
          typographyDeemphasized: X,
        },
      },
      {
        item: {
          className: X,
          icon: X,
          typographyHeader: X,
          typographyDeemphasized: X,
        },
      },
    ],
  };

Structure of the map so far:

const details = files.column.map((singleFile) => {
    return (
      <div className={classes.column}>
        <div className={classes.indicator}>
          <div className={classes.item}>
            <Icon fontSize="small" className={singleFile.item.className}>
              {singleFile.item.icon}
            </Icon>
            <Typography className={`${classes.header} ${classes.typography}`} variant="subtitle1">
              &nbsp;&nbsp;{singleFile.item.typographyHeader}
            </Typography>
          </div>
          <div className={classes.item}>
            <Icon fontSize="small" className={classes.hidden}>
              check_circle
            </Icon>
            <Typography className={`${classes.deemphasized} ${classes.typography}`} variant="body2">
              {singleFile.item.typographyDeemphasized}
            </Typography>
          </div>
        </div>
      </div>
    );
  });

That doesn't look like a valid object. In JS objects cannot have duplicate keys (column), is that a typo in the example code, or do you actually have multiple column keys? — DBS
– DBS, Commented Jun 21, 2021 at 13:45
"I would like to map through the array..." This sounds like an XY problem. Instead of describing how you are trying to do something, please tell us what you want. Show us what you want the output to be. — Code-Apprentice
– Code-Apprentice, Commented Jun 21, 2021 at 15:32
@MrVoland I have updated my answer. Please check whether this works for you — Nitheesh
– Nitheesh, Commented Jun 21, 2021 at 15:50

Nitheesh · Accepted Answer · 2021-06-21 15:29:42Z

Hope this is the Array that you are referring.

In this the key columnOne and columnTwo are dynamic.

const files = {
    columnOne: [
      {
        item: {
          className: X,
          icon: X,
          typographyHeader: X,
          typographyDeemphasized: X,
        },
      },
      {
         item: {
          className: X,
          icon: X,
          typographyHeader: X,
          typographyDeemphasized: X,
        },
      },
      {
         item: {
          className: X,
          icon: X,
          typographyHeader: X,
          typographyDeemphasized: X,
        },
      },
    ],
    columnTwo: [
      {
         item: {
          className: X,
          icon: X,
          typographyHeader: X,
          typographyDeemphasized: X,
        },
      },
      {
         item: {
          className: X,
          icon: X,
          typographyHeader: X,
          typographyDeemphasized: X,
        },
      },
      {
        item: {
          className: X,
          icon: X,
          typographyHeader: X,
          typographyDeemphasized: X,
        },
      },
    ],
  };

For the above structure the below mentioned state and render function will work...

Working Fiddle. https://jsfiddle.net/dj3k0pg6/

 this.state = {
  files: {
    columnOne: [
      {
        item: {
          className: 'X',
          icon: 'X',
          typographyHeader: 'Header 1',
          typographyDeemphasized: 'X',
        },
      },
      {
        item: {
          className: 'X',
          icon: 'X',
          typographyHeader: 'Header 2',
          typographyDeemphasized: 'X',
        },
      },
      {
        item: {
          className: 'X',
          icon: 'X',
          typographyHeader: 'Header 3',
          typographyDeemphasized: 'X',
        },
      },
    ],
    columnTwo: [
      {
        item: {
          className: 'X',
          icon: 'X',
          typographyHeader: 'Header 4',
          typographyDeemphasized: 'X',
        },
      },
      {
        item: {
          className: 'X',
          icon: 'X',
          typographyHeader: 'Header 5',
          typographyDeemphasized: 'X',
        },
      },
      {
        item: {
          className: 'X',
          icon: 'X',
          typographyHeader: 'Header 6',
          typographyDeemphasized: 'X',
        },
      },
    ],
  }
}
}



render() {
    const details = Object.keys(this.state.files).map((key) => {
      return this.state.files[key].map((file) => {
        return (
          <div className="column" key={file.item.typographyHeader}>
            <div className="indicator">
              <div className="item">
                {file.item.typographyHeader}
              </div>
            </div>
          </div>
        );
      })
    })
    return (
      <div>
        {details}
      </div>
    )
  }

Hm, your solution is not working for me - it doesn't render anything this time :(

Collectives™ on Stack Overflow

Mapping through an object with arrays in React

1 Answer 1

2 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

2 Comments

Your Answer

Sign up or log in

Post as a guest

Related