js怎么比较两个时间的年数

function compareYears(date1, date2) {
    // 创建Date对象
    const d1 = new Date(date1);
    const d2 = new Date(date2);

    // 获取年份
    const year1 = d1.getFullYear();
    const year2 = d2.getFullYear();

    // 比较年份
    if (year1 > year2) {
        return `${year1} 大于 ${year2}`;
    } else if (year1 < year2) {
        return `${year1} 小于 ${year2}`;
    } else {
        return `${year1} 等于 ${year2}`;
    }
}

// 示例使用
const dateStr1 = "2020-01-01";
const dateStr2 = "2023-05-15";
console.log(compareYears(dateStr1, date2)); // 输出: 2020 小于 2023

function compareYearsUTC(date1, date2) {
    const d1 = new Date(date1);
    const d2 = new Date(date2);

    const year1 = d1.getUTCFullYear();
    const year2 = d2.getUTCFullYear();

    if (year1 > year2) {
        return `${year1} 大于 ${year2}`;
    } else if (year1 < year2) {
        return `${year1} 小于 ${year2}`;
    } else {
        return `${year1} 等于 ${year2}`;
    }
}

console.log(compareYearsUTC(dateStr1, dateStr2)); // 输出: 2020 小于 2023