// 计算一组数组中key值相同的数量 let arr = [ { name: 'Mokeke', age: 10, }, { name: 'caixia', age: 10, }, { name: 'caixia', age: 10, }, { name: 'zijian', age: 11, }, ] 一、 function accont(arr) { let obj = {} for (let i = 0; i < arr.length; i++) { if (obj[arr[i].age]) { obj[arr[i].age] += 1 } else { obj[arr[i].age] = 1 } } return obj } 二、 function accont(arr) { let obj = {} for (let i = 0; i < arr.length; i++) { if (obj[arr[i].age]) { obj[arr[i].age] += 1 continue } obj[arr[i].age] = 1 } return obj } let result = accont(arr) console.log(result, 'result') for(let i in result){ console.log(`键值为${i}的数量为${result[i]}`) }
// 判断数组某一个键值的个数 function account(text,arr,key){ debugger let temp = {} let count = 0 if(!temp[key]){ temp[key] = text arr.forEach(item => { if(item[key] === temp[key]){ count += 1 } }) } return count } let caleResult = account('Mokeke',arr, 'name') console.log(caleResult,'count')