let employeeList = [ { id: -1, name: "Toàn", age: 33, gender: "male" // male, female, other }, { id: 1, name: "Tiến", age: 33, gender: "male" // male, female, other }, { id: 2, name: "Hải", age: 33, gender: "male" // male, female, other } ] function deleteItem(id) { // for(let i = 0; i < employeeList.length; i++) { // if(id == employeeList[i].id) { // employeeList.splice(i, 1) // break // } // } employeeList = employeeList.filter(em => em.id != id) } function findById(id, arr) { // for (let i = 0; i < arr.length; i++) { // if (id == arr[i].id) { // return arr[i] // } // } return arr.find(em => em.id == id) } let findEmp = findById(1, employeeList) findEmp.age = 18 console.log("findEmp", findEmp) console.log("employeeList", employeeList)