JavaScript判断两个数组是否存在相同元素的四种方法

function hasRepeat(arr1,arr2){
    if(arr1.length===0){
        return false;
    }
    if(arr2.length===0){
        return false;
    }
    var flag = false;
    for(var i=0;i<arr1.length;i++){
        if(arr2.indexOf(arr1[i]) >= 0){
            flag=true;
            break;
        }
    }
    return flag;
}

function hasDuplicate(arr1, arr2) {
  for (let i = 0; i < arr1.length; i++) {
    for (let j = 0; j < arr2.length; j++) {
      if (arr1[i] === arr2[j]) {
        return true;
      }
    }
  }
  return false;
}

function hasDuplicate(arr1, arr2) {
  const set1 = new Set(arr1);
  return arr2.some((item) => set1.has(item));
}

function hasDuplicate(arr1, arr2) {
  const set1 = new Set(arr1);
  const set2 = new Set(arr2);
  let intersect = new Set([...set1].filter( => set2.has(e)));
  return intersect.size > 0 
}