Shorten string without cutting words in JavaScript

Question

I'm not very good with string manipulation in JavaScript, and I was wondering how you would go about shortening a string without cutting any word off. I know how to use substring, but not indexOf or anything really well.

Say I had the following string:

text = "this is a long string I cant display"

I want to trim it down to 10 characters, but if it doesn't end with a space, finish the word. I don't want the string variable to look like this:

"this is a long string I cant dis"

I want it to finish the word until a space occurs.

Answer 1

If I understand correctly, you want to shorten a string to a certain length (e.g. shorten "The quick brown fox jumps over the lazy dog" to, say, 6 characters without cutting off any word).

If this is the case, you can try something like the following:

var yourString = "The quick brown fox jumps over the lazy dog"; //replace with your string.
var maxLength = 6 // maximum number of characters to extract

//Trim and re-trim only when necessary (prevent re-trim when string is shorted than maxLength, it causes last word cut) 
if(yourString.length > trimmedString.length){
    //trim the string to the maximum length
    var trimmedString = yourString.substr(0, maxLength);

    //re-trim if we are in the middle of a word and 
    trimmedString = trimmedString.substr(0, Math.min(trimmedString.length, trimmedString.lastIndexOf(" ")))
}