What is the shorthand and best way to find intersection?
f = ["A","B","C","D","E","F"]; //might be less than 8
b = [1,0,0,1,0,0,0,0]; //always 8 elements
Desired resulting array ["A","D"]
5 Answers
You could use Array#filter
var f = ["A", "B", "C", "D", "E", "F"],
b = [1, 0, 0, 1, 0, 0, 0, 0],
r = f.filter((_, i) => b[i]);
console.log(r);2 Comments
RomanPerekhrest
Desired resulting array ["A","C"]
Nina Scholz
i assume to filter the same place.
Assuming your f array is never longer than your b array
f.filter((item, index) => b[index] === 1);
If you're wanting this completely shorthand you can rename item and index and drop the === 1:
f.filter((a, i) => b[i]);
var f = ["A","B","C","D","E","F"]; //might be less than 8
var b = [1,0,0,1,0,0,0,0]; //always 8 elements
console.log(f.filter((a, i) => b[i]));
2 Comments
RomanPerekhrest
Desired resulting array ["A","C"]
James Donnelly
@RomanPerekhrest in my answer I state: "...and assuming you meant D instead of C".
var f = ["A","B","C","D","E","F"];
var b = [1,0,0,1,0,0,0,0];
var res = f.filter(function(e, i) {
return b[i]; // short for return b[i] === 1;
});
console.log(res);Or even shorter using arrow functions like this:
var f = ["A","B","C","D","E","F"];
var b = [1,0,0,1,0,0,0,0];
var res = f.filter((e, i) => b[i]);
console.log(res);5 Comments
RomanPerekhrest
Desired resulting array ["A","C"]
ibrahim mahrir
@RomanPerekhrest I've noticed and I'm still waiting for the user to clarify! It's is probably just a typo!
kind user
@RomanPerekhrest It would be totally pointless if the desired result would be
[A,C].ibrahim mahrir
He just re-editted the question It was a typo! As Kind user said there is no logic for it to be
[A, C]!RomanPerekhrest
@Kinduser, everyone realized that i was
[A,C](not big deal). The OP should have presented the proper conditionsAnother Way :
$(function(){
f = ["A","B","C","D","E","F"];
b = [1,0,0,1,0,0,0,0];
x = [];
$.each(b,function(key, value){
value?x.push(f[key]):'';
});
console.log(x)
});7 Comments
Nina Scholz
jquery goes always, but why?
ibrahim mahrir
@NinaScholz He is probably a jQuery-phobic needsmorejquery.com!
Majid Nayyeri
@ibrahimmahrir :))
Nina Scholz
@ibrahimmahrir, more the opposite, jqueryphilic
Majid Nayyeri
@NinaScholz wanna stop analyzing me ? :-D
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Since for loops are faster than filter method i suggest this:
var results = [];
for(var i=0;i<b.length;i++){
if (b[i]) results.push(f[i]);
}
1 Comment
Nina Scholz
you don't need
== 1 with truthy values.
"C", at it's the third element inf? shouldn't beD?