mayank :
So suppose my array looks like this:
let langArr = [
["python", "blue"]
,["python", "blue"]
,["c++", "red"]
,["java", "yellow"]
,["javascript", "lime"]
,["shell", "green"]
,["c++", "red"]
];
what I want is something like this:
{
python: {
count: 2
color: "blue"
}
c++: {
count: 2
color: "red"
}
java: {
count: 1
color: "yellow"
}
and so on...
}
I tried reduce method like this:
let langCount = langArr.reduce((lang, [name, color]) => {
lang[name] = (lang[name] || 0) + 1;
lang[color] = 'color';
return lang;
}, {});
console.log(langCount);
but I get this output:
{
python: 2
blue: "color"
c++: 2
red: "color"
java: 1
yellow: "color"
and so on...
}
Nina Scholz :
You need an object for each language.
This approach takes an object as default value if lang[name]
is falsy, like undefined
.
The pattern
variable = variable || value;
works with a logical OR ||
:
- if
variable
has a truthy value, take this value, - if
variable
has a falsy value, takevalue
instead.
let langArr = [["python", "blue"], ["python", "blue"], ["c++", "red"], ["java", "yellow"], ["javascript", "lime"], ["shell", "green"], ["c++", "red"]],
langCount = langArr.reduce((lang, [name, color]) => {
lang[name] = lang[name] || { count: 0, color };
lang[name].count++;
return lang;
}, {});
console.log(langCount);
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