get snippet text using javascript?

I 开发者_StackOverflowhave a long text. ex:

var text = "get snippet text using javascript?";

How can I write a method to get the snippet, not substring:

Ex: snippet(text,10) -> "get snippet..." not "get snippe" (10 characters). it means if the last character not a space or dot, we must get more characters until reach space or dot.

Any help?

Not tested thoroughly:

function getSnippet(text, length) {
    var rx = new RegExp("^.{" + length + "}[^ ]*");
    return rx.exec(text)[0];
}
console.log(getSnippet("get snippet text using javascript?", 1));  // get
console.log(getSnippet("get snippet text using javascript?", 3));  // get
console.log(getSnippet("get snippet text using javascript?", 10)); // get snippet
console.log(getSnippet("get snippet text using javascript?", 11)); // get snippet

You can add the ellipsis when the returned string is shorter than original string.

function intelligentlyTruncate( text, threshhold )
{    
    for(var i = threshhold; i < text.length; i++ )
    {
        if( /^\s/.test(text.substr( i, 1 ) ) )
            return text.substr( 0, i ); // + '...' if you want the elipsis.
    }
    return text;
}

console.log( intelligentlyTruncate("get snippet text using javascript?", 5) );
// get snippet

And if you want to have a maximum instead of a minimum (so it will never be longer than a given value):

function intelligentlyTruncate( text, threshhold )
{    
    for(var i = threshhold - 1; i >= 0; i-- )
    {
        if( /^\s/.test(text.substr( i, 1 ) ) )
            return text.substr( 0, i ); // + '...' if you want the elipsis.
    }
    return text;
}


console.log( intelligentlyTruncate("get snippet text using javascript?", 5) );
// get

You can use indexOf and specify the start point to find the next space.

var text = "get snipped text using javascript?";
    function getComplete(str, len) {
        if (str.length > len) {
            var i = str.indexOf(" ", len);
            return str.substring(0, i);
        }
        return str;
    }
getComplete(text, 10) // "get snipped";

A prototype riff on theprogrammer's answer:

String.prototype.getComplete = function(len) {
   var str = this;
   if (str.length > len) {
       var i = str.indexOf(" ", len);
       return str.substring(0, i);
   }
   return str;
}

//Usage
mystr = mystr.getComplete(500);

Not sure I understand your question completely, but I guess regular expression can be used in this case:

text.match(/^(\S+ [^ .]+)/)[1]

returns

"get snippets"

function snippet(str,len) { newStr=str.substring(0, len);var i = len; while(str[i]!=' ' && str[i]!='.') newStr+=str[i++]; return newStr+"...";
}