Could you please help in achieve below output compare var1 and var2 and obtain output based of var2 where key are provided in string of array
var1 = {a:1, b:2, c:3, d:4};
var2 = ['a', 'd'];
Output should be:
var3 = {a:1, d:4};
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4 Answers
const var3 = var2.reduce((acc, cur) => {
if (var1[cur]) {
acc[cur] = var1[cur];
}
return acc;
}, {})
2 Comments
Gautham Shetty
Thanks for the solution i have use case. where key is not available in array for example. var var1 = {a:1,b:2,c:3,d:4}; var var2 =['a','d','f']; i have output like var3 = {a:1, d:4};
MorKadosh
@GauthamShetty a simple
if will solve that. see editUsing .forEach
var var1 = {a:1,b:2,c:3,d:4}; var var2 =['a','d'];
var var3 = {};
var2.forEach(i=>{
var3[i] = var1[i]
})
console.log(var3)2 Comments
Gautham Shetty
Thanks for the solution i have use case. where key is not available in array for example. var var1 = {a:1,b:2,c:3,d:4}; var var2 =['a','d','f']; i have output like var3 = {a:1, d:4};
ABGR
I didn’t get you. The case you provided would still work with this solution.
You can use Object.entries and iterate
var1 = {a:1,b:2,c:3,d:4}; var2 =['a','d'];
o={}
for(let [k,v] of Object.entries(var1)){
var2.forEach(x=>{if(k==x){
o[k]=v
}})
}
console.log(o)
1 Comment
Gautham Shetty
Thanks for the solution i have use case. where key is not available in array for example. var var1 = {a:1,b:2,c:3,d:4}; var var2 =['a','d','f']; i have output like var3 = {a:1, d:4};
You can .map() each key in var2 to an object containing the key and its associated value. From that mapped array, you can assign each object to an object using Object.assign():
const var1 = {a:1,b:2,c:3,d:4};
const var2 = ['a','d', 'f'];
const var3 = Object.assign({}, ...var2.map(id => id in var1 ? {[id]: var1[id]} : {}));
console.log(var3);Another approach could be to use Object.fromEntries() if you can support it:
const var1 = {a:1,b:2,c:3,d:4};
const var2 = ['a','d', 'f'];
const var3 = Object.fromEntries(var2.filter(id => id in var1).map(id => [id, var1[id]]));
console.log(var3);2 Comments
Gautham Shetty
Thanks for the solution i have use case. where key is not available in array for example. var var1 = {a:1,b:2,c:3,d:4}; var var2 =['a','d','f']; i have output like var3 = {a:1, d:4};
Nick Parsons
@GauthamShetty I've updated my answer to handle these cases