【js实现】在排序数组中,找出给定数字的出现次数,比如[1, 2, 3, 4, 4, 5, 3, 21, 2, 4, 2, 45]中2的出现次数是3次
思路:数组循环把值给到对象,相同的对象健值+1,最后再把对象遍历
var singleNumbers = function (nums,number) {
var returnArr = [];
var obj = {};
for (let i = 0; i < nums.length; i++) {
obj[nums[i]] = obj[nums[i]] + 1 || 1
}
for (let r in obj) {
if (r == number) {
console.log(obj[r])//结果是3,意思是数字2出现3次
}
}
};
singleNumbers([1, 2, 3, 4, 4, 5, 3, 21, 2, 4, 2, 45],2)