编辑代码

//JSRUN引擎2.0，支持多达30种语言在线运行，全仿真在线交互输入输出。 
console.log("Hello world!            -  js.jsrun.net ");
var tag;
var tag2 = null;
var tag3 = true;
var tag4 = false;
var taglAsNumber = Number (tag1);
var tag2AsNumber = Number (tag2);
var tag3AsNumber = Number (tag3);
var tag4AsNumber = Number (tag4);
console.log (taglAsNumber) ; console.log (tag2AsNumber) ; console.log (tag3AsNumber);
console.log (tag4AsNumber);