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47 lines
1.3 KiB
JavaScript
47 lines
1.3 KiB
JavaScript
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// http://2ality.com/2015/01/es6-set-operations.html
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// Difference (a \ b): create a set that contains those elements of set a that are not in set b.
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// This operation is also sometimes called minus (-).
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// var a = [1,2,3];
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// var b = [4,3,2];
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// utilArrayDifference(a, b)
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// [1]
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// utilArrayDifference(b, a)
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// [4]
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export function utilArrayDifference(a, b) {
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var other = new Set(b);
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return Array.from(new Set(a))
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.filter(function(v) { return !other.has(v); });
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}
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// Intersection (a ∩ b): create a set that contains those elements of set a that are also in set b.
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// var a = [1,2,3];
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// var b = [4,3,2];
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// utilArrayIntersection(a, b)
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// [2,3]
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export function utilArrayIntersection(a, b) {
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var other = new Set(b);
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return Array.from(new Set(a))
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.filter(function(v) { return other.has(v); });
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}
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// Union (a ∪ b): create a set that contains the elements of both set a and set b.
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// var a = [1,2,3];
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// var b = [4,3,2];
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// utilArrayUnion(a, b)
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// [1,2,3,4]
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export function utilArrayUnion(a, b) {
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var result = new Set(a);
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b.forEach(function(v) { result.add(v); });
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return Array.from(result);
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}
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// Returns an Array with all the duplicates removed
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// var a = [1,1,2,3,3];
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// utilArrayUniq(a)
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// [1,2,3]
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export function utilArrayUniq(a) {
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return Array.from(new Set(a));
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}
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