使用 Array.map 并过滤对象数组，尝试删除包含 NaN 值的项目

Question

As stated in title, i'm trying to remove items that hold values that are NaN in an array of objects.

distanceMatrix = [{
    'Av. Vieira Souto, 168 - Ipanema, Rio de Janeiro - RJ, 22420-004, Brazil': 'ZERO_RESULTS'
},
{
    'Rynek Główny 12, 33-332 Kraków, Poland': 1540493
},
{
    '27 Derb Lferrane, Marrakech 40000, Morocco': 2539727
},
{
    'R. Roberto Símonsen, 122 - Sé, São Paulo - SP, 01017-020, Brazil': 'ZERO_RESULTS'
}]

I am trying to run this function without avail:

distanceMatrix.map((location, index)=>{
    Object.values(location)
    .filter((item)=>{return !isNaN(item[0]) ? item[0] : null});
});

I am looking to reshape distanceMatrix to have items that hold only number values. Would be happy to know what i'm doing wrong.

Answer 1

An easy solution to remove objects that contain a value which is not a number would be a filter:

const filteredDistanceMatrix = distanceMatrix.filter(location => {
    const value = Object.values(location)[0]
    return !isNaN(value)
})

The filter returns a copy of distanceMatrix without the objects containing a NaN value.

Answer 2

For what your sample of data shown, the objects on your array consist only of a pair of key and value . So Object.values() will return an array with only one value . You can check if that value is a valid number, and if not, filter the whole object out:

 const distanceMatrix = [ {'Av. Vieira Souto, 168 - Ipanema, Rio de Janeiro - RJ, 22420-004, Brazil': 'ZERO_RESULTS'}, {'Rynek Główny 12, 33-332 Kraków, Poland': 1540493}, {'27 Derb Lferrane, Marrakech 40000, Morocco': 2539727}, {'R. Roberto Símonsen, 122 - Sé, São Paulo - SP, 01017-020, Brazil': 'ZERO_RESULTS'} ]; let res = distanceMatrix.filter(o => !isNaN(+Object.values(o)[0])); console.log(res);

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On the previous example, we use Unary Plus to coerces the only value of the array returned by Object.values() to a number, then we check if the result of the casting is a number or not with isNan() .

Answer 3

这可以用于任何长度的键值对内部对象

distanceMatrix.map(location => Object.keys(location).reduce((acc, k) => { acc[k] = !isNaN(location[k]) ? location[k] : null; return acc },{}))

Answer 4

your current code outputs

[
    [], 
    [1540493], 
    [2539727], 
    []
]

I'm guessing you want to then reduce this array to a list of good values

const data = [
  { 'Av. Vieira Souto, 168 - Ipanema, Rio de Janeiro - RJ, 22420-004, Brazil': 'ZERO_RESULTS' },
  { 'Rynek Główny 12, 33-332 Kraków, Poland': 1540493 },
  { '27 Derb Lferrane, Marrakech 40000, Morocco': 2539727 },
  { 'R. Roberto Símonsen, 122 - Sé, São Paulo - SP, 01017-020, Brazil': 'ZERO_RESULTS' }
]

const out =[];
data.forEach(loc => {
    const results = Object.values(loc).filter(l => !isNaN(l));
    out.push(...results);
});
// [1540493, 2539727]

Answer 5

This will work:

 distanceMatrix = [ { 'Av. Vieira Souto, 168 - Ipanema, Rio de Janeiro - RJ, 22420-004, Brazil': 'ZERO_RESULTS' }, { 'Rynek Główny 12, 33-332 Kraków, Poland': 1540493 }, { '27 Derb Lferrane, Marrakech 40000, Morocco': 2539727 }, { 'R. Roberto Símonsen, 122 - Sé, São Paulo - SP, 01017-020, Brazil': 'ZERO_RESULTS' } ] var result = distanceMatrix.filter((item)=>{ var itemValue = parseInt(Object.values(item)[0]); return !isNaN(itemValue); }); console.log(result);