Javascript：如何从字符串末尾删除标点符号

Question

Disclaimer: I'm new to programming! I did look through SO to find the answer to this question before posting, but didn't find the answer I need.

Right now, the API I'm working with is returning a variable: 'description'. 'description' is a dynamic, 250-character string with punctuation.

I have to truncate the string to 110 characters and then insert an ellipsis after it. This is easy enough - I've been using something like:

description.slice(0,110) + "..."

But the above is problematic because I have no way of predicting what character my string will truncate on. If it truncates on punctuation or a white space, the result looks really silly:

I've been reading a lot of similar inquiries where developers want to know how to take off one punctuating character at the end of a string. But I might have to take off several punctuating characters, depending on how much punctuation or white space is returned with the variable.

Can anyone advise me on the best way to go about this? If I can provide any additional information, please let me know.

Answer 1

Per my comment, I would approach it slightly differently, to assure whole words.

 var string = "This is a sentence. A long sentence that should be broken up so it's not too long. Got it? Good. How long. does it get?"; var excerpt = createExcerpt(string); console.log(excerpt); // Function to parse a sentence into an excerpt, based on whole words function createExcerpt(string, maxLength) { // Set a default value of maxLength of 110 maxLength = maxLength | 110; // If it's not too long, don't do anything if (string.length <= maxLength) { return string; } // Break it up into words var words = string.split(' '); var excerpt = ''; // Loop over the words in order words.forEach(function(word) { // Build a test string to see if it's too long test = excerpt + ' ' + word; // If it's too long, then break out of the loop if (test.length > maxLength) { return false; } // Otherwise, set the excerpt to the new test string excerpt = test; }); // Remove any extra spaces / dots at the end of the excerpt excerpt = excerpt.replace(/[\\s|\\.]+$/i, ''); // Return the excerpt with ellipses return excerpt + '...'; } 

Answer 2

You could use the trim to remove the extra spaces at the end :

var description = description.slice(0,110).trim(); //trim to remove spaces

Then add a condition to check if there's a dot at the end if yes add two others else add three punctuations :

if (description[description.length-1] === ".")
    description += '..';
else
    description += '...';

Hope this helps.

 var description = "Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum."; description = description.slice(0,110).trim(); if (description[description.length-1] === ".") description += '..'; else description += '...'; console.log(description); 

Snippet with . and spaces at the end :

 var description = "Lorem ipsum dolor sit amet,consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore. magna aliqua."; description = description.slice(0,110).trim(); if (description[description.length-1] === ".") description += '..'; else description += '...'; console.log(description); 

Answer 3

I think this will work!

function truncateWholeWords (text, maxLength) {
    maxLength = maxLength || 110; 
    var length = 0;

    return text.split(' ').filter(function (word) {
        length += (word.length+1);
        return length <= maxLength;
    }).join(' ').replace(/([.,\/#!$%\^&\*;:{}=\-_`~()\]\[])+$/g, "") + '...';

}