map循环
	let array = [1, 2, 3, 4, 5];
	let newArray = array.map((item) => {
	    return item * item;
	})
	console.log(newArray)  // [1, 4, 9, 16, 25]

	find循环
	this.state={
			nwelist:[
				{id:1,title:'这是1'},
				{id:2,title:'这是2'},
				{id:3,title:'这是3'},
				{id:4,title:'这是4'}
				]
		}
		let findResult = this.state.nwelist.find(item=>{
			if(4==item.id){
				return item
			}
		})
		console.log(findResult)// {id: 4, title: '这是4'}