NaN

//数据类型之NaN

var name_0 = "Null";

var name_1 = 10;

var name_2 ="我是字符串";

var name_3 ="10";

var name_4 ="undefined";

console.log(isNaN(name_0));

console.log(isNaN(name_1));

console.log(isNaN(name_2));

console.log(isNaN(name_3));

console.log(isNaN(name_4));