Node.js – util.formatWithOptions() method

The util.formatWithOptions() method works in the same way as the util.format() method. The only difference between the two is that the formatWithOptions() method takes an inspectOptions argument that specifies options that are passed along the util.inspect() method.

Syntax

util.formatWithOptions(inspectOptions, format, [args])

Parameters

The parameters are defined below:

• inspectOptions − These options will be used to inspect the object passed along this method.
• format − This parameter takes input for the format type of the input value passed.

Example 1

Create a file with the name "formatWithOptions.js" and copy the following code snippet. After creating the file, use the command "node formatWithOptions.js" to run this code.

// Node.js util.formatWithOptions() method

// Importing the util module
const util = require('util');

function fun() {
   // Passing different options along the format
   var val0 = util.formatWithOptions(
      { depth:0, colors: true },
      'See object %O', { foo: 21 });

   var val1 = util.formatWithOptions(
      { colors: true, showProxy : true },
      '%s:%s:%s', 'a', 'b', 'c');

   var val2 = util.formatWithOptions(
      { showHidden: true, colors: true },
      '%s:%s', 'raj', 'rahul');

   var val3 = util.formatWithOptions(
      { breakLength: 3, colors: true },
      10, 20, 30);

   var val5 = util.formatWithOptions(
      { compact: true }, '%% : %s', 567);

   console.log(val0, '
', val1, '
',
      val2, '
', val3, '
', val5);
}
// Function call
fun();

Output

C:\home\node>> node formatWithOptions.js
See object { foo: 21 }
a:b:c
raj:rahul
10 20 30
% : 567

Example 2

// Node.js util.formatWithOptions() method

// Importing the util module
const util = require('util');

console.log("1. ", util.formatWithOptions(
   { colors: true },
   '%%: %s', 'John', 'Cena', -0));

console.log("2. ", util.formatWithOptions(
   {
      showHidden: false, depth: 0,
      colors: true
   }, '%s', 'fun', Object.create(null,
   { [Symbol.toStringTag]: { value: 'function' } })));

console.log("3. ", util.formatWithOptions(
   { colors: true }, '%o',
   class Bar { }, 'fun', 78987965465464));

console.log("4. ", util.formatWithOptions(
   { depth: 0, colors: true }, '%o:%d',
   class Foo { get [Symbol.toStringTag]()
      { return 'fun'; } }, 'fun',
   78987965465464));

Output

C:\home\node>> node formatWithOptions.js
1. %: John Cena 0
2. fun [Object: null prototype] [function] {}
3. { [Function: Bar]
[length]: 0,
[prototype]: Bar { [constructor]: [Circular] },
[name]: 'Bar' } fun 78987965465464
4. { [Function: Foo]
   [length]: 0,
   [prototype]:
   Foo [fun] {
      [constructor]: [Circular],
      [Symbol(Symbol.toStringTag)]: [Getter] },
   [name]: 'Foo' }:NaN 78987965465464