Using Lodash truncate
Jun 10, 2022
The truncate
function allows you to shorten a string if it is longer than a specifed length.
It will shorten the string and replace the last characters of the shortened string with the characters you specify, or the default ...
.
It takes three parameters:
- length (number), the maximum length of the string.
- omission (string), the string to indicate text is omitted.
- separator (RegExp | string), the separator pattern to truncate to.
const _ = require('lodash');
const example = 'Masteringjs.io is a great website to learn JavaScript fundamentals, Mongoose, Vue, and other JavaScript libraries.';
const result = _.truncate(example, {
length: 39
});
result; // Masteringjs.io is a great website to...
const close = _.truncate(example, {
length: 36,
omission: '.',
});
close; // Masteringjs.io is a great website.
Separator
The separator
argument is handy for preventing JavaScript from breaking words when truncating. If you pass a separator
, JavaScript will truncate at the last instance of separator
before length.
const _ = require('lodash');
const example = 'Masteringjs.io is a great website to learn JavaScript fundamentals, mongoose, vue, and other fun JavaScript libraries.';
const short = _.truncate(example, {
length: 23, // 'Masteringjs.io is a gre'.length
separator: ' '
});
short; // Masteringjs.io is a...
Because ' '
is the separator, Lodash backtracked and cut off the string at the last space before index 23. Even though index 23 is halfway through "great", truncate()
avoided breaking up words.