//获取光标
function doGetCaretPosition (oField) {
// Initialize
var iCaretPos ;
// IE Support
if (document.selection) {
// Set focus on the element
oField.focus();
// To get cursor position, get empty selection range
var oSel = document.selection.createRange();
// Move selection start to 0 position
oSel.moveStart('character', -oField.value.length);
// The caret position is selection length
iCaretPos = oSel.text.length;
}
// Firefox support
else if (oField.selectionStart || oField.selectionStart == '0')
iCaretPos = oField.selectionStart;
console.log(iCaretPos)
// Return results
return iCaretPos;
}
//截取字符串
String.prototype.insert = function (index, item) {
var temp = [];
for (var i = 0; i < this.length; i++) {
temp.push(this[i]);
}
temp.splice(index, 0, item);
console.log(temp.join(""))
return temp.join("")
};
//js
string.insert(0,'jia')