// program to write to console // passing number console.log(8); // passing string console.log('hello'); // passing variable const x = 'hello'; console.log(x); // passing function function sayName() { return 'Hello John'; } console.log(sayName()); // passing string and a varia...
constfs=require('fs');consterrorFs=fs.createWriteStream('./error-log.txt');process.stderr.write=errorFs.write.bind(errorFs);constinfoFs=fs.createWriteStream('./info-log.txt');process.stdout.write=infoFs.write.bind(infoFs);console.error('This is an error message.');console.log('This ...
address:"中国香港"};console.log(user.age);//访问对象中的属性,未定义vari;console.log(i);//变量未赋值functionf(n1){console.log(n1);}varresult=f();//参数未赋值console.log(result);//当函数没有返回值时为undefined 结果: 关于null 和 undefined...
console.warn(message) Parameters ParameterDescription messageRequired. The message (warning) to write to the console. More Examples Example Use an object as the warning message: constmyObj = {firstname:"John", lastname:"Doe"}; console.warn(myObj); ...
以及上面使用innerHTML而不是innerText的函数。我也试过使用 document.write(); 但这会清除页面的其余部分。最后,我在字符串前面添加了一些随机字符,并尝试使用 replace("!@#","") 函数来替换这些字符以模仿“编辑它以任何方式似乎都能正常显示”,我注意到了。
process.stdout.write = infoFs.write.bind(infoFs); console.error('This is an error message.'); console.log('This is a log message.'); 运行此代码时,传递给 error() 和 log() 的消息将输出到相应的文件,而不是控制台。 5.warn()
If you guess that theconsole.log()call would either outputundefinedor throw an error, you guessed incorrectly. Believe it or not, it will output10. Why? In most other languages, the code above would lead to an error because the “life” (i.e., scope) of the variableiwould be restrict...
console.log(num1.toFixed(2)); // 输出 "0.61" 而非 "0.62"如果需要更精确的四舍五入,可以使用其他方法,例如将数字乘以某个倍数、调用 Math.round() 函数并手动处理小数位数等,如下实例:实例 function roundNumber(number, decimals) { const factor = 10 ** decimals; return Math.round(number * fact...
Writing into the HTML output usingdocument.write(). Writing into an alert box, usingwindow.alert(). Writing into the browser console, usingconsole.log(). Using innerHTML To access an HTML element, you can use thedocument.getElementById(id)method. ...
console.log(x); } foo(); // "functional scope" console.log(x); // "global scope" 这里,foo()和console.log(x)的结果与预期一致。但是,如果去掉第二个变量又会发生什么呢? var x = "global scope"; function foo() { x = "functional scope"; console.log(x); ...