Converts an array of objects to a comma-separated values (CSV) string that contains only the columns
specified.
Use Array.prototype.join(delimiter)
to combine all the names in columns
to create the first row.
Use Array.prototype.map()
and Array.prototype.reduce()
to create a row for each object, substituting non-existent values with empty strings and only mapping values in columns
.
Use Array.prototype.join('\n')
to combine all rows into a string.
Omit the third argument, delimiter
, to use a default delimiter of ,
.
代码片段
const JSONtoCSV = (arr, columns, delimiter = ',') =>
[
columns.join(delimiter),
...arr.map(obj =>
columns.reduce(
(acc, key) => `${acc}${!acc.length ? '' : delimiter}"${!obj[key] ? '' : obj[key]}"`,
''
)
)
].join('\n');
使用样例
JSONtoCSV([{ a: 1, b: 2 }, { a: 3, b: 4, c: 5 }, { a: 6 }, { b: 7 }], ['a', 'b']); // 'a,b\n"1","2"\n"3","4"\n"6",""\n"","7"'
JSONtoCSV([{ a: 1, b: 2 }, { a: 3, b: 4, c: 5 }, { a: 6 }, { b: 7 }], ['a', 'b'], ';'); // 'a;b\n"1";"2"\n"3";"4"\n"6";""\n"";"7"'