前端: JavaScript: Set的集合操作 about blog

[xvno]

• Union
• Difference, Symmetric Difference
• Intersection

function cloneSet(set0) {
  let ret = new Set();
  set0.forEach(i => {
    ret.add(i);
  })
  return ret;
}
function getUnion(set1, set2) {
  let ret = cloneSet(set1);
  set2.forEach(i => {
    ret.add(i);
  });
  return ret;
}

function getDiff (set1, set2) {
  let ret = cloneSet(set1);
  set2.forEach(i => {
    ret.delete(i);
  });
  return ret;
}
function getSymDiff(set1, set2) {
  let diff1 = getDiff(set1, set2);
  let diff2 = getDiff(set2, set1);
  return getUnion(diff1, diff2);
}

function getIts (set1, set2) {
  let ret = cloneSet(set1);
  set2.forEach(i => {
    if(set1.has(i)) {
      ret.add(i);
    }
  });
  return ret;
}

let a = new Set([1,2,3,4,5,6]);
let b = new Set([4,5,6,7,8,9]);

console.log('getUnion: ', getUnion(a,b));
console.log('getDiff: ', getDiff(a,b));
console.log('getDiff: ', getDiff(b,a));
console.log('getSymDiff: ', getSymDiff(a, b));
console.log('getIts: ', getIts(a,b));

[xvno]

getUnion:  Set { 1, 2, 3, 4, 5, 6, 7, 8, 9 }
getDiff:  Set { 1, 2, 3 }
getDiff:  Set { 7, 8, 9 }
getSymDiff:  Set { 1, 2, 3, 7, 8, 9 }
getIts:  Set { 1, 2, 3, 4, 5, 6 }

[xvno]

把这些函数修改为接受一个参数, 挂在Set.prototype下作为原型方法调用.