遇到这样一个需求,输入框在输入银行卡号的时候,需要每4位自动插入一个空格
以下是实现
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>Document</title> <script> function getCaretPosition(obj) { var result = 0; if ('selectionStart' in obj) { result = obj.selectionStart; } else { try{ var rng; if (obj.tagName == "textarea") { rng = event.srcElement.createTextRange(); rng.moveToPoint(event.x, event.y); } else { rng = document.selection.createRange(); } rng.moveStart("character", -event.srcElement.value.length); re