var arr = [{ key: '01', value: '乐乐' }, { key: '02', value: '博博' }, { key: '03', value: '淘淘' },{ key: '04', value: '哈哈' },{ key: '01', value: '乐乐' }]; // 方法1:利用对象访问属性的方法,判断对象中是否存在key var result = []; var obj = {}; for(var i =0; i<arr.length; i++){ if(!obj[arr[i].key]){ result.push(arr[i]); obj[arr[i].key] = true; } } const result = [] const obj = {} for (let i = 0; i < data.length; i++) { if (!obj[data[i].key]) { result.push(data[i]) obj[data[i].key] = true } } console.log('result ', result) console.log(result); // [{key: "01", value: "乐乐"},{key: "02", value: "博博"},{key: "03", value: "淘淘"},{key: "04", value: "哈哈"}] // 方法2:利用reduce方法遍历数组,reduce第一个参数是遍历需要执行的函数,第二个参数是item的初始值 var obj = {}; arr = arr.reduce(function(item, next) { obj[next.key] ? '' : obj[next.key] = true && item.push(next); return item; }, []); console.log(arr); // [{key: "01", value: "乐乐"},{key: "02", value: "博博"},{key: "03", value: "淘淘"},{key: "04", value: "哈哈"}]