I have const tab where I want to change property isActive from boolean to 'on' or 'off' depending on if it's true or false.

   const tab = [
   {id:'0',original:{lineId:'4', isActive:false, length: '3'}},
   {id:'1',original:{lineId:'5', isActive:true, length: '4'}},
   {id:'2',original:{lineId:'6', isActive:false, length: '7'}}
  ];

I tried to use .map() but I do something wrong. Can You please suggest where is the issue ?

const newTab = tab.map(x => x.original.isActive === false ? 'off' : x.original.isActive === true ? 'on' : x);

This is how newTab should look like after change:

  const newTab = 
[
    {id:'0',original:{lineId:'4', isActive:'off', length: '3'}},
      {id:'1',original:{lineId:'5', isActive:'on', length: '4'}},
      {id:'2',original:{lineId:'6', isActive:'off', length: '7'}}
     ];

With current code it returns changed isActive property only:

const newTab = ["off", "on", "off"]

thanks !

I have const tab where I want to change property isActive from boolean to 'on' or 'off' depending on if it's true or false.

   const tab = [
   {id:'0',original:{lineId:'4', isActive:false, length: '3'}},
   {id:'1',original:{lineId:'5', isActive:true, length: '4'}},
   {id:'2',original:{lineId:'6', isActive:false, length: '7'}}
  ];

I tried to use .map() but I do something wrong. Can You please suggest where is the issue ?

const newTab = tab.map(x => x.original.isActive === false ? 'off' : x.original.isActive === true ? 'on' : x);

This is how newTab should look like after change:

  const newTab = 
[
    {id:'0',original:{lineId:'4', isActive:'off', length: '3'}},
      {id:'1',original:{lineId:'5', isActive:'on', length: '4'}},
      {id:'2',original:{lineId:'6', isActive:'off', length: '7'}}
     ];

With current code it returns changed isActive property only:

const newTab = ["off", "on", "off"]

thanks !

• javascript
• reactjs

3 Answers 3

You can use spread syntax, and you can update variables in map method.

tab.map((e) => (
    {
        ...e,
        original: {
            ...e.original,
            isActive: e.original.isActive ? 'on' : 'off'
        }
    }
))

You want to return the entire object, not just on or off inside your map. You can condense this using ...(spread operator) and only modify isActive while returning everything else as is:

const tab = [{
    id: '0',
    original: {
      lineId: '4',
      isActive: false,
      length: '3'
    }
  },
  {
    id: '1',
    original: {
      lineId: '5',
      isActive: true,
      length: '4'
    }
  },
  {
    id: '2',
    original: {
      lineId: '6',
      isActive: false,
      length: '7'
    }
  }
];

const newTab = tab.map(item => ({
  ...item,
  original: {
    ...item.original,
    isActive: item.original.isActive ? 'on' : 'off',
  }
}));

console.log(newTab)

you can use a mapping and return a JSON by copying the values.

const tab = [
    { id: '0', original: { lineId: '4', isActive: false, length: '3' } },
    { id: '1', original: { lineId: '5', isActive: true, length: '4' } },
    { id: '2', original: { lineId: '6', isActive: false, length: '7' } }
];

const tab2 = tab.map(e => {
        return {
            id: e.id,
            original: {
                lineId: e.original.lineId,
                isActive: e.original.isActive ? 'on' : 'off',
                length: e.original.length
            }
        }
    });

Output : Image Output