Summary of console usage in JavaScript or node

1 //Create App.js page2 //One: page code3Console.log ("Log Information");4 //Execute (node app.js) in the page this file will see the log message in the console: "Log Information"5 //execute in another way: node App.js 1>info.txt (1 for redirect standard output stream);6 //this time you will see a info.txt file in App.js's sibling directory, with "log information" in it.7 8 //two: Output all strings sequentially9Console.log ("%s", "First", "second");Ten //output Result: First Second One  A //three. Execute after converting an object to a normal string -Console.log ("%s", "Guoyansi", {name: "Dr. Sisi"}); - //output: Guoyansi {name: ' Dr. Sisi '} the  - //Four: - //Convert a string as a numeric value -Console.log ("%d", "25.6"); + //output Result: 25.6 -Console.log ("%d", "Guoyansi"); + //output Result: Guoyansi A  at //Five output% -Console.log ("percent"); - //output Result:% -Console.log ("percent", "Gys"); - //output Result:% Gys -  in //VI output CONSOLE.ERROR information to a file - //page code: toConsole.error ("Guoyansi is Error"); + //start this page with node App.js 2>err.txt - //There is one more Err.txt file in the sibling directory. There is also "Guoyansi is Error" in the file the  * //Seven start a file javascript.js that does not exist directly on the command line, such as: $ //node Javascript.js 2>info.txtPanax Notoginseng //output: One more file Info.txt in the directory where the command line is located; - //the contents of the Info.txt file are as follows the  +  A /* the module.js:340 + throw err; -  ^ $ error:cannot Find module ' E:\node\gys\javascript.js ' $ At function.module._resolvefilename (module.js:338:15) - At function.module._load (module.js:280:25) - At Function.Module.runMain (module.js:497:10) the At startup (node.js:119:16) - At Node.js:906:3Wuyi  */ the  - //Eight: The use of Console.warn is the same as the use of Console.error () Wu  - //Nine: Console.time () and console.timeend () outputs the execution time of the intermediate code (note: The parameters of the timing and timeend must be exactly the same) AboutConsole.time ("For Loop Time:") $ varA=0; -  for(vari=0;i<10000000000000;i++){ -a++; - } AConsole.timeend ("For Loop Time:") + /* the * The 10.console.trace () method outputs the stack information at the current location as a standard error message. -  *  */ $  the varobj={ theName: "Guoyansi", theAge:23, theEatfunction(){} - } in console.trace (obj); the //Output Result:

I don't know if you can read it, I can't understand it anyway.

1 // 10: Console.assert () evaluates the expression result, if the expression evaluates to False, Outputs a message string and throws a Assertionerror exception

2 console.assert ("g" = = = = "S", "G not equal to S");

Summary of console usage in JavaScript or node