(Node.js) JavaScript console

See more JavaScript Examples

Note: This example requires Chilkat v11.4.0 or greater.

Install Chilkat for Node.js and Electron using npm at Chilkat npm packages for Node.js Chilkat npm packages for Electron on Windows, Linux, MacOS

var os = require('os');
if (os.platform() == 'win32') {  
  var chilkat = require('@chilkat/ck-node23-win64'); 
} else if (os.platform() == 'linux') {
    if (os.arch() == 'arm') {
        var chilkat = require('@chilkat/ck-node23-linux-arm');
    } else if (os.arch() == 'arm64') {
        var chilkat = require('@chilkat/ck-node23-linux-arm64');
    } else {
        var chilkat = require('@chilkat/ck-node23-linux-x64');
    }
} else if (os.platform() == 'darwin') {
  var chilkat = require('@chilkat/ck-node23-mac-universal');
}

function chilkatExample() {

    var success = false;

    // This example demonstrates using the built-in console object.
    // The Javascript run in this example is shown below.

    // Load the JavaScript from a file.
    var sbScript = new chilkat.StringBuilder();
    success = sbScript.LoadFile("qa_data/js_tests/test_console.js","utf-8");
    if (success == false) {
        console.log(sbScript.LastErrorText);
        return;
    }

    var js = new chilkat.Js();
    var result = new chilkat.JsonObject();

    // Run the JavaScript
    // Results (not console output) go to result.
    // Note: Eval returns the completion value of the script. This is generally the value of the last evaluated expression.
    // In this case, the last evaluated expression is console.log which does not calculate a value. Therefore, it returns undefined.
    success = js.Eval(sbScript,result);
    if (success == false) {
        console.log(sbScript.LastErrorText);
        return;
    }

    // We can look at the result, which is "undefined", which is normal and expected.
    console.log(result.Emit());
    // The result JSON is: {"type":"undefined","value":"undefined"}

    // The console output is retrieved by calling ConsoleOutputSb
    var sbOut = new chilkat.StringBuilder();
    js.ConsoleOutputSb(sbOut);
    console.log(sbOut.GetAsString());

}

chilkatExample();

// Chilkat Js console emits CRLF line endings on Windows, and LF line endings on non-Windows.

console.log("Hello %s, %d, %f", "World", 248, 12.05);
// Output: Hello World, 248, 12.05

// If there are more arguments than the number of specifiers, the extra arguments are output, separated by spaces:
console.log('%s:%s', 'foo', 'bar', 'baz');
// Output: foo:bar baz

// If the first argument does not contain a valid format specifier, outputs a string that is the concatenation of all arguments separated by spaces:
console.log(1,2,3);
// Output: 1 2 3

//If only one argument is passed, it is returned as it is without any formatting:
console.log("%% %s");
// Output: %% %s

const myApp = {
    appName: "Example",
    version: 1.0,
    isDebug: true,
    supportedTypes: ["string", "number", "object"],
    settings: {
        maxWidgets: 1024,
        allowIO: true
    }
};

// %O: Emits the same as JSON.stringify(myConfig, null, 2)
console.log("myApp: %O", myApp);
// Output:
// myApp: {
//   "appName": "Example",
//   "version": 1,
//   "isDebug": true,
//   "supportedTypes": [
//     "string",
//     "number",
//     "object"
//   ],
//   "settings": {
//     "maxWidgets": 1024,
//     "allowIO": true
//   }
// }

console.log("App: %s (Version %d)", myApp.appName, myApp.version);
// Output: App: Chilkat Js (Version 1)