Node.js console.trace() Method

The console.trace() method is an inbuilt application programming interface of the console module which is used to print stack trace messages to stderr in a newline. Similar to console.error() method. 

Syntax:

console.trace(message, args);

Parameters: This method has two parameters as mentioned above and described below:

• message: This parameter specifies the message to be printed.
• args: It is an optional parameter that specifies the parameters to be passed as substitution values in the message. All passed args are sent to util.format().

Return Value: This method doesn't return anything but print the 'Trace:' string followed by the formatted message to stderr in a newline and stack trace to the current position in the code. 

Example 1: The below examples illustrate the use of console.trace() method in Node.js.

Filename: app.js 

// Node.js program to demonstrate the
// console.trace() method

// Accessing console module
const console = require('console');

// Calling console.trace() method
console.trace("stack teace sample");

console.trace(
    "stack trace sample with args: %d", 39);

Run the app.js file using the following command:

node app.js

Output:

Trace: stack teace sample
at Object. (C:\nodejs\g\console\console_trace.js:4:9)
at Module._compile (internal/modules/cjs/loader.js:776:30)
at Object.Module._extensions..js (internal/modules/cjs/loader.js:787:10)
at Module.load (internal/modules/cjs/loader.js:653:32)
at tryModuleLoad (internal/modules/cjs/loader.js:593:12)
at Function.Module._load (internal/modules/cjs/loader.js:585:3)
at Function.Module.runMain (internal/modules/cjs/loader.js:829:12)
at startup (internal/bootstrap/node.js:283:19)
at bootstrapNodeJSCore (internal/bootstrap/node.js:622:3)
Trace: stack trace sample with args: 39
at Object. (C:\nodejs\g\console\console_trace.js:5:9)
at Module._compile (internal/modules/cjs/loader.js:776:30)
at Object.Module._extensions..js (internal/modules/cjs/loader.js:787:10)
at Module.load (internal/modules/cjs/loader.js:653:32)
at tryModuleLoad (internal/modules/cjs/loader.js:593:12)
at Function.Module._load (internal/modules/cjs/loader.js:585:3)
at Function.Module.runMain (internal/modules/cjs/loader.js:829:12)
at startup (internal/bootstrap/node.js:283:19)
at bootstrapNodeJSCore (internal/bootstrap/node.js:622:3)

Example 2: The below examples illustrate the use of the console.trace() method in Node.js. 

Filename: app.js 

// Node.js program to demonstrate the
// console.trace() method

// Accessing console module
const console = require('console');

// Calling console.trace() method
console.trace("stack trace message: "
               + "at %s: line no: %d ", "ff()", 96);

let isTrace = true;

console.custom_trace = function (message) {
    if (isTrace) {
        console.trace(message);
    }
}

console.custom_trace("custom trace message");

Run the app.js file using the following command:

node app.js

Output:

Trace: stack trace message: at ff(): line no: 96
at Object. (C:\nodejs\g\console\console_trace_1.js:4:9)
at Module._compile (internal/modules/cjs/loader.js:776:30)
at Object.Module._extensions..js (internal/modules/cjs/loader.js:787:10)
at Module.load (internal/modules/cjs/loader.js:653:32)
at tryModuleLoad (internal/modules/cjs/loader.js:593:12)
at Function.Module._load (internal/modules/cjs/loader.js:585:3)
at Function.Module.runMain (internal/modules/cjs/loader.js:829:12)
at startup (internal/bootstrap/node.js:283:19)
at bootstrapNodeJSCore (internal/bootstrap/node.js:622:3)
Trace: custom trace message
at Console.console.custom_trace (C:\nodejs\g\console\console_trace_1.js:11:13)
at Object. (C:\nodejs\g\console\console_trace_1.js:14:9)
at Module._compile (internal/modules/cjs/loader.js:776:30)
at Object.Module._extensions..js (internal/modules/cjs/loader.js:787:10)
at Module.load (internal/modules/cjs/loader.js:653:32)
at tryModuleLoad (internal/modules/cjs/loader.js:593:12)
at Function.Module._load (internal/modules/cjs/loader.js:585:3)
at Function.Module.runMain (internal/modules/cjs/loader.js:829:12)
at startup (internal/bootstrap/node.js:283:19)
at bootstrapNodeJSCore (internal/bootstrap/node.js:622:3)

Note: The above program will compile and run by using the node filename.js command. 

Reference: https://nodejs.org/api/console.html#console_console_trace_data_args