修改state中數組對象某一個字段(state中某個屬性為對象或數組時，需要修改該對象中的某一個屬性)

this.state = { listData: [ {name: "張三", age: "20"}, {name: "李四", age: "21"}, ], obj: { name: "王五", age: "22", } }

change = (index) => { const listData = [...this.state.listData];   //復制數組--淺拷貝
    const obj = Object.assign({}, this.state.obj, { age: "21" }); this.setState({ listData: listData.map((item, idx) => idx === index ? {...item, name:  "趙六"} : item), obj: obj, }) }