变量的解构赋值 // 数组的解构赋值 let [a,b,c] = [1,2,3]; //1,2,3 let [a,b,c] = [,123,]; //undefined 123 undefined let [a=111,b,c] = [,123,]; //111 123 undefined console.log(a,b,c); 对象的解构赋值 let {foo,bar} = {foo : 'hello',bar : 'hi'};//hello hi let {foo,bar} = {bar :