<html><head><title>javascript In the typeof The use of </title><script>//1. Basic typesvar x = 123;var y = "abc";var z = true;//alert(typeof x);//number//alert(typeof y);//string//alert(typeof z);//boolean//2. Reference type. The type is objectvar arr = new Array();var date = new Date();var str = new String("abc");//alert(typeof arr);//object//alert(typeof date);//object//alert(typeof str);//object//3. Object type, which can be understood as the simulation of classes in javascript is realized through functionalert(typeof Array);//functionalert(typeof Date);//functionalert(typeof String);//function</script></head><body></body></html>