sprintf

What is sprintf?

The sprintf npm package is a JavaScript implementation of the sprintf function from the C programming language. It allows for formatted string creation using a format string and a list of arguments. This is useful for creating strings with dynamic content in a structured and readable way.

What are sprintf's main functionalities?

Basic String Formatting

This feature allows you to insert variables into a string using placeholders. In this example, '%s' is a placeholder for a string, and 'world' is the value that gets inserted.

const sprintf = require('sprintf-js').sprintf;
const formattedString = sprintf('Hello %s!', 'world');
console.log(formattedString); // Output: Hello world!

Number Formatting

This feature allows you to format numbers within a string. In this example, '%d' is a placeholder for an integer, and '42' is the value that gets inserted.

const sprintf = require('sprintf-js').sprintf;
const formattedNumber = sprintf('The number is %d.', 42);
console.log(formattedNumber); // Output: The number is 42.

Floating Point Formatting

This feature allows you to format floating-point numbers to a specified number of decimal places. In this example, '%.2f' formats the number to two decimal places.

const sprintf = require('sprintf-js').sprintf;
const formattedFloat = sprintf('The value is %.2f.', 3.14159);
console.log(formattedFloat); // Output: The value is 3.14.

Padding and Alignment

This feature allows you to pad and align strings within a specified width. In this example, '%10s' pads the string 'test' to a total width of 10 characters, aligning it to the right.

const sprintf = require('sprintf-js').sprintf;
const formattedString = sprintf('%10s', 'test');
console.log(formattedString); // Output: '      test'

Other packages similar to sprintf

util

The 'util' package is a built-in Node.js module that provides various utility functions, including 'util.format', which is similar to sprintf. It supports string formatting with placeholders like %s, %d, and %j. However, it is less feature-rich compared to sprintf and is more focused on general utility functions.

string-format

The 'string-format' package provides a simple way to format strings using placeholders. It supports named placeholders and is more flexible in terms of syntax compared to sprintf. However, it does not support as many formatting options as sprintf.

printf

The 'printf' package is another implementation of the C-style printf function in JavaScript. It offers similar functionality to sprintf, including support for various placeholders and formatting options. It is a good alternative if you are looking for a package with similar capabilities.

README

sprintf() for node

Disclaimer

This was originally just an adoption of a browser library to node.js.
Since that library is now itself a node.js module, you should use that one: alexei/sprintf.js

Or just install it via npm:

npm install sprintf-js

There is also a built-in util.format.

Install

This package is not maintained anymore. See Disclaimer above.

npm install sprintf

How to

Works exactly like http://www.diveintojavascript.com/projects/javascript-sprintf, except that it exports those two functions:

sprintf = require('sprintf').sprintf;
vsprintf = require('sprintf').vsprintf;

Have fun!

Copyright/License

Copyright (c) 2007-2013, Alexandru Marasteanu <hello [at) alexei (dot] ro> All rights reserved.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

• Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
• Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
• Neither the name of this software nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.