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ViewsUnable to access JavaScript Object property from CSV file
I am having a hard time figuring out how to access a property of my javascript object.
I have a Node JS application that downloads a CSV file from the WHO with covid data and then I loop through each of these entries. Here is how I loop through each of the CSV entries:
fs.createReadStream("data.csv")
.pipe(csv())
.on("data", (data) => {
//process data
})
.on("end", () => {
});
Here is one sample of the output when I run console.log(data)
{
'Name': 'Niger',
'WHO Region': 'Africa',
'Cases - cumulative total': '6203',
'Cases - cumulative total per 100000 population': '25.63',
'Cases - newly reported in last 7 days': '64',
'Cases - newly reported in last 7 days per 100000 population': '0.26',
'Cases - newly reported in last 24 hours': '10',
'Deaths - cumulative total': '205',
'Deaths - cumulative total per 100000 population': '0.85',
'Deaths - newly reported in last 7 days': '1',
'Deaths - newly reported in last 7 days per 100000 population': '0',
'Deaths - newly reported in last 24 hours': '0'
}
If I run typeof data I am getting object.
I would like to access some properties of this object.
If I output data["WHO Region"] I get "Africa". So this works.
However, I am unable to access the name of those object.
console.log(data["Name"]);
console.log(data.hasOwnProperty("Name"));
Outputs respectively undefined and false
Even though the name property is present within the object.
I have also tried to list the keys of the object with Object.keys(data) and here is the result:
[ 'Name', 'WHO Region', 'Cases - cumulative total', ... ]
So apparently the key Name does exist but I can't access it for some reason. Am I missing something there?
2 answers
Answer question0
You have invisible symbol in the Name property of the object. You can see it if you past result of the console.log in the browser console:
Check your original CSV file and search for this invisible character.
EDIT: This symbol is ZWNBSP (Zero Width No-Break Space) at the start of the file.
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The issue is caused by the Byte Order Mark (BOM) at the start of the file, represented by the byte sequence 0xEF,0xBB,0xBF corresponding to the UTF-8 codepoint U+FEFF.
An easy workaround for your code would be to replace this like so:
const results = [];
fs.createReadStream('data.csv')
.pipe(csv())
.on('data', (data) => {
// Replace BOM in key
const key1 = Object.keys(data)[0];
data = { ...data, [key1.replace(/\uFEFF/, '')]: data[key1] };
results.push(data);
})
.on('end', () => {
results.forEach(result => {
console.log(`Name: ${result["Name"]}`);
})
});
or
You could open the file in Nodepad++ and using the Encoding menu change it from UTF-8-BOM to UTF-8 and saving.