jquery SMS character calculator with 7-bit and 16b

问题:

I have a text field to type sms message both in english and chinese language. As I have searched, 1 sms can only have 1120 bits. Each english character is 7 bit so it can be 1120/7 = 160 characters and for chinese each character is 16 bits so that is 1120/16 = 70 characters. I need to use jquery to show the words written and words remaining under the text field. how do i do this?

回答1:

Characters can be single byte ,double byte, triple byte and so on. So single byte follows in a particular range.Same thing is true for other characters.Based on this I have created following functions that will calculate the size of a string on the basis of memory

function getByteLength(normal_val) {
    // Force string type
    normal_val = String(normal_val);

    var byteLen = 0;
    for (var i = 0; i < normal_val.length; i++) {
        var c = normal_val.charCodeAt(i);
        byteLen +=  c < (1 <<  7) ? 1 :
                    c < (1 << 11) ? 2 :
                    c < (1 << 16) ? 3 :
                    c < (1 << 21) ? 4 :
                    c < (1 << 26) ? 5 :
                    c < (1 << 31) ? 6 : Number.NaN;
    }
    return parseInt(byteLen)*8;
} 

I have created a js fiddle that will work for you. http://jsfiddle.net/paraselixir/d83oaa3v/6/

回答2:

have a look at below snippet, this counts total characters and total number of message.

you can change the value of $maxVal to 160/70

$(document).ready(function () {

var $remaining = $('#charNum'),
    $messages = $remaining.prev();
    $maxVal = 160;

$('.word-counter').keyup(function(){
    var chars = this.value.length,
        messages = Math.ceil(chars / $maxVal),
        remaining = messages * $maxVal - (chars % (messages * $maxVal) || messages * $maxVal);

    $remaining.text(remaining + ' characters remaining');
    $messages.text(messages + ' message(s) / ');
});




});

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<textarea name="" id="SMSMessage" cols="30" rows="2" class="form-ctrl word-counter foo-value"></textarea>
<span class="error-message word-counter">0  message(s) / </span><span id="charNum" class="error-message">160 characters remaining</span>

回答3:

there is a package that we can use for this issue, checkout: https://github.com/danxexe/sms-counter