sprintf() lite for JavaScript
Low-fat implementation of the sprintf() function for JavaScript that gets you all you need.
For simple string templates:
{person1} gets easily triggered when {person2} makes fun of CS:GO.
For easy Swagger and other API spec tools interation as path/route parameters:
/path/to/{success}/should/not/{be}/hard
/path/to/:success/should/not/:be/hard
Description
string sprintf (string format [, mixed args [, mixed ... ]])
format A string that contains the text to be returned, it can optionally contain embedded format specifiers and keys that are replaced by the values specified in subsequent additional arguments and formatted as requested.
args A number of mixed type arguments for the replacement. Can be a string, array or an object.
Returns a string produced according to the formatting string merged with replacement values.
Compatible specifiers
- %d — print an integer as is
- %u — print an integer as is
- %f — print a float as is
- %s — print a string as is
Named keys
- :key - print a value of an object key as is.
- {key} - print a value of an object key as is.
Install
npm install sprintf-lite
Use
ES5
var sprintf = require('sprintf-lite').default
ES6
import sprintf from 'sprintf-lite'
Examples IRL
Example #1 Basic anonymous keys replacement
Quick string formatting.
sprintf('%s + %d = %s', 'Two', 3, 'Five')
sprintf('/my/%s/api/%s/number/%d', ['awesome', 'endpoint', 1])
The above example will output:
Two + 3 = Five
/my/awesome/api/endpoint/number/1
Example #2 Basic named keys replacement
Embedding object keys into configuration strings or any string templates.
sprintf('Dear {firstName} {lastName}, ...', {firstName: 'John', lastName: 'Doe'})
sprintf('/users/{userId}/orders/{orderId}', {userId: 654321, orderId: 987654321})
sprintf('/users/:userId/orders/:orderId', {userId: 654321, orderId: 987654321})
The above example will output:
Dear John Doe, ...
/users/654321/orders/987654321
/users/654321/orders/987654321
Example #3 Argument swapping and reuse
Keys can be used multiple times in any arbitrary order.
sprintf('In America, you {do} {what}, in Soviet Russia, {what} {do}s YOU!', {do: 'install', what: 'a package'})
The above example will output:
In America, you install a package, in Soviet Russia, a package installs YOU!