javascript - 在字符串的错误索引中插入的字符

Question

我正在尝试在特定字符串中插入其他字符。

function sample(x) {
            if (x.value.length > 2 && x.value.length < 5) { 
                var first = x.value.substring(0, 2) + "'";
                var second = x.value.substring(2, x.value.length) + "''";
                x.value = first + "" + second ; }           
}

<input id="txt" type="text" placeholder="onkeypress" onkeypress="sample(this)" value="" /><br />
<input id="txt1" type="text" placeholder="onchange" onchange="sample(this)" value="" />

通过在 htmlinput 中使用 onchange 属性，代码可以完美运行。但这也可以使用 onkeypress 属性运行吗？如果输入值为 1006，则结果应为 10'06''。帮助。谢谢。

Answer 1

试试这个:

You need to replace the quotes('/") before manipulating the string. Also use keyup event. Refer this to understand the purpose of each events. onkeyup is fired when the key is released

function sample(x) {
  x.value = x.value.replace(/[\'\"]/g, '');
  if (x.value.length > 2 && x.value.length < 5) {
    var first = x.value.substring(0, 2) + "'";
    var second = x.value.substring(2, x.value.length) + "''";
    x.value = first + "" + second;
  }
}

<input id="txt" type="text" placeholder="onkeypress" onkeyup="sample(this)" value="" />
<br/>
<input id="txt1" type="text" placeholder="onchange" onchange="sample(this)" value="" />