Node.js console.warn() Function

The console.warn() function from console class of Node.js is used to display the warning messages on the console. It prints to stderr with newline.

Note: This function is an alias of console.error() function.

Syntax:

console.warn( [data][, ...args] )

Parameter: This function can contains multiple parameters. The first parameter is used for the primary message and other parameters are used for substitution values.

Return Value: The function returns the warning message.

Below programs demonstrate the working of the console.warn() function:

Program 1:

function displayWarning(x) {
    console.warn(`GeeksforGeeks is a ${x} portal`);
}

const x = 'Computer Science';

displayWarning(x);

Output:

GeeksforGeeks is a Computer Science portal

Program 2:

function compareNumber(x, y) {

    // Check condition
    if (x > y) {
        console.warn(`${x} is greater then ${y}`);
    }
    else {
        console.warn(`${x} is less then or equal to ${y}`);
    }
}

// Store number to variable
x = 100;
y = 50;

compareNumber(x, y);

Output:

100 is greater then 50