console.log(typeof 456);
console.log(typeof 3.14);
console.log(typeof '2'); // string
console.log(typeof Number('2')); // number
console.log(typeof Infinity); // number
console.log(typeof '');
console.log(typeof 'javascript');
console.log(typeof String(12));
console.log(typeof true);
console.log(typeof n);
console.log(typeof {x: 98});
console.log(typeof [5, 7, 0, 2]);
console.log(typeof new Date());
console.log(typeof function() {});
console.log(typeof class C {});
console.log(typeof Math.cos);
let x = 12;
console.log(typeof x + ' abc');
console.log(typeof (x + ' abc'));
/*
run:
"number"
"number"
"string"
"number"
"number"
"string"
"string"
"string"
"boolean"
"undefined"
"object"
"object"
"object"
"function"
"function"
"function"
"number abc"
"string"
*/