javascript - Count the number of spaces of the current line in a textarea

Question

How can I count the number of spaces of the current line in a textarea

asdf
   asdf
asdf

If my cursor is current on line 2 then the result should be: 3

Answer 1

您需要拆分 textarea 的字符串值，然后：

var textString = //pull data from textarea
var textArray = textString.split("\n");
for(var i=0; i<textArray.length; i++) {
    var count = textArray[i].match(/ /g); //regex to get any number of spaces 
    alert(count.length);
}

http://jsfiddle.net/2qfHn/

Answer 2

这是代码：

window.onload = function () {
    var ta = document.getElementById('ta'); //set your textarea's id
    ta.onclick = function (e) {
        var lineNo = ta.value.substr(0, ta.selectionStart).split(/\r?\n|\r/).length,
            lineText = ta.value.split(/\r?\n|\r/)[lineNo - 1],
            numOfSpaces = lineText.split(/\s/).length - 1;
        console.log(lineNo, lineText, numOfSpaces);
    }
}

这是小提琴。

注意：在某些浏览器中不起作用。如需跨浏览器支持，请参阅这篇文章。 textarea.selectionStart