如何计算一个数组中的元素在另一个数组中出现的次数

function countOccurrences(arr1, arr2) {
  var result = {};
  
  for (var i = 0; i < arr1.length; i++) {
    var count = 0;
    
    for (var j = 0; j < arr2.length; j++) {
      if (arr1[i] === arr2[j]) {
        count++;
      }
    }
    
    result[arr1[i]] = count;
  }
  
  return result;
}

// 示例用法
var array1 = [1, 2, 3, 4, 5];
var array2 = [1, 2, 2, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 5];
var occurrences = countOccurrences(array1, array2);
console.log(occurrences);