I have a simple 2d array containing x, y coordinates like this:
var c = [
[1,10]
[2,11]
[3,12]
[4,13]
[5,15]
];
How can I extract only pairs that satisfy TWO conditions (one for x, one for y) and put those in its own array? For instance:
for Each of c {
if (x > 3 && y > 13) {
push.NewArray
}
}
Newbie to JS here and can't find this on the web. Thanks in advance for any help.
With filter instead of push, like this:
const filtered = c.filter(([x, y]) => x > 3 && y > 13);
var c = [
[1, 10],
[2, 11],
[3, 12],
[4, 13],
[5, 15]
];
const filtered = c.filter(([x, y]) => x > 3 && y > 13);
console.log(filtered);You need commas to separate array items too.
The destructuring there is equivalent to:
const filtered = c.filter((arr) => arr[0] > 3 && arr[1] > 13);
You can use the function Array.prototype.filter which executes a predicate (aka handler) in order to extract the elements in the array who satisfies a specific condition, in your case x > 3 && y > 13.
You can use the function filter as follow:
let c = [ [1, 10], [2, 11], [3, 12], [4, 13], [5, 15]],
filtered = c.filter(function([x, y])/*This is the predicate (aka handler)*/ {
return x > 3 && y > 13
});
console.log(filtered);In the code snippet above (function([x, y]){}), we used something called destructuring assignment
An approach using arrow functions:
let c = [ [1, 10], [2, 11], [3, 12], [4, 13], [5, 15]],
filtered = c.filter(([x, y]) => x > 3 && y > 13);
console.log(filtered);