Zig Requires Chilkat v11.4.0+

JavaScript console

See more JavaScript Examples

Demonstrates console output using Chilkat JavaScript. Zig

const std = @import("std");
const chilkat = @import("chilkat");

pub fn main(init: std.process.Init) !void {
    const alloc = init.arena.allocator();

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

    // Load the JavaScript from a file.
    const sb_script = try chilkat.StringBuilder.init();
    defer sb_script.deinit();
    sb_script.loadFile("qa_data/js_tests/test_console.js", "utf-8") catch {
        std.debug.print("{s}\n", .{try sb_script.getLastErrorText(alloc)});
        return;
    };

    const js = try chilkat.Js.init();
    defer js.deinit();
    const result = try chilkat.JsonObject.init();
    defer result.deinit();

    // 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.
    js.eval(sb_script, result) catch {
        std.debug.print("{s}\n", .{try sb_script.getLastErrorText(alloc)});
        return;
    };

    // We can look at the result, which is "undefined", which is normal and expected.
    std.debug.print("{s}\n", .{try result.emit(alloc)});
    // The result JSON is: {"type":"undefined","value":"undefined"}

    // The console output is retrieved by calling ConsoleOutputSb
    const sb_out = try chilkat.StringBuilder.init();
    defer sb_out.deinit();
    js.consoleOutputSb(sb_out);
    std.debug.print("{s}\n", .{try sb_out.getAsString(alloc)});
}

JavaScript

// 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)