In certain arrays, blank entries are stored separately in a designated section reserved for null values

Question

In certain arrays, blank entries are stored separately in a designated section reserved for null values

var dataList = [ 
                 { date: '2019-08-08', class: null, users: 21 },
                 { date: '2019-08-08', class: 'lower', users: 21 },  
                 { date: '2019-08-08', class: 'upper', users: 3}
                 { date: '2019-08-08', class: 'middle', users: 5}

               ];

If any element in the array has a key with the value null, I would like to change it to be stored under the "Others" key instead. Each array contains multiple dates and one null value.

Replace null with "Others"
var dataList = [ 
                { date: '2019-08-08', class: 'Others', users: 21 },
                { date: '2019-08-08', class: 'lower', users: 21 },  
                { date: '2019-08-08', class: 'upper', users: 3}
                { date: '2019-08-08', class: 'middle', users: 5}
              ];

javascript arrays null key

Answer 1

Answer №1

Utilizing a forEach iteration

var dataList = [ 
                 { date: '2019-08-08', class: null, users: 21 },
                 { date: '2019-08-08', class: 'lower', users: 21 },  
                 { date: '2019-08-08', class: 'upper', users: 3},
                 { date: '2019-08-08', class: 'middle', users: 5}

               ];
dataList.forEach(function(item){
if(item.date==null)
item.date='Others'
if(item.class==null)
item.class='Others'
if(item.users==null)
item.users='Others'
})
console.log(dataList)

Answer 2

Utilizing a forEach iteration

var dataList = [ 
                 { date: '2019-08-08', class: null, users: 21 },
                 { date: '2019-08-08', class: 'lower', users: 21 },  
                 { date: '2019-08-08', class: 'upper', users: 3},
                 { date: '2019-08-08', class: 'middle', users: 5}

               ];
dataList.forEach(function(item){
if(item.date==null)
item.date='Others'
if(item.class==null)
item.class='Others'
if(item.users==null)
item.users='Others'
})
console.log(dataList)

Answer 3

Answer №2

To implement this functionality, utilize the map function as demonstrated below:

 

const data = [ 
             { date: '2020-12-15', category: null, count: 32 },
             { date: '2020-12-15', category: 'low', count: 45 },  
             { date: '2020-12-15', category: 'high', count: 10},
             { date: '2020-12-15', category: 'medium', count: 22}

           ];

const result = data.map(({ category: cat, ...rest }) => ({ category: cat == null ? "Other" : cat, ...rest }));

console.log(result);

Answer 4

To implement this functionality, utilize the map function as demonstrated below:

 

const data = [ 
             { date: '2020-12-15', category: null, count: 32 },
             { date: '2020-12-15', category: 'low', count: 45 },  
             { date: '2020-12-15', category: 'high', count: 10},
             { date: '2020-12-15', category: 'medium', count: 22}

           ];

const result = data.map(({ category: cat, ...rest }) => ({ category: cat == null ? "Other" : cat, ...rest }));

console.log(result);

Answer 5

Answer №3

Implementing the array.map() method would be the best approach:

By using the map() function, you can generate a new array by applying a specified function to each element in the original array.

var dataList = [ 
                 { date: '2019-08-08', class: null, users: 21 },
                 { date: '2019-08-08', class: 'lower', users: 21 },  
                 { date: '2019-08-08', class: 'upper', users: 3},
                 { date: '2019-08-08', class: 'middle', users: 5}

               ];
               
let newList = dataList.map( (obj) => obj.class == null? { ...obj, class: "Other" } : obj );

If you require checking for any key in obj rather than just the class key, please indicate here so that I can modify my response accordingly.

Answer 6

Implementing the array.map() method would be the best approach:

By using the map() function, you can generate a new array by applying a specified function to each element in the original array.

var dataList = [ 
                 { date: '2019-08-08', class: null, users: 21 },
                 { date: '2019-08-08', class: 'lower', users: 21 },  
                 { date: '2019-08-08', class: 'upper', users: 3},
                 { date: '2019-08-08', class: 'middle', users: 5}

               ];
               
let newList = dataList.map( (obj) => obj.class == null? { ...obj, class: "Other" } : obj );

If you require checking for any key in obj rather than just the class key, please indicate here so that I can modify my response accordingly.

Answer 7

Answer №4

This piece of code is quite straightforward:

dataList = dataList.map(x => {
    x.class = x.class || "Others";
    return x;
})

var dataList = [ 
                 { date: '2019-08-08', class: null, users: 21 },
                 { date: '2019-08-08', class: 'lower', users: 21 },  
                 { date: '2019-08-08', class: 'upper', users: 3},
                 { date: '2019-08-08', class: 'middle', users: 5}

               ];
               
dataList = dataList.map(x => {
    x.class = x.class || "Others";
    return x;
})

console.log(dataList)

Answer 8

This piece of code is quite straightforward:

dataList = dataList.map(x => {
    x.class = x.class || "Others";
    return x;
})

var dataList = [ 
                 { date: '2019-08-08', class: null, users: 21 },
                 { date: '2019-08-08', class: 'lower', users: 21 },  
                 { date: '2019-08-08', class: 'upper', users: 3},
                 { date: '2019-08-08', class: 'middle', users: 5}

               ];
               
dataList = dataList.map(x => {
    x.class = x.class || "Others";
    return x;
})

console.log(dataList)

In certain arrays, blank entries are stored separately in a designated section reserved for null values

Answer №1

Answer №2

Answer №3

Answer №4

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