[英]Change a single value of a textbox Javascript
I want to change only one value of an input, example: in the input income "xy" I want to change is only "and" Suppose a new value is "p", and "x" leave. 我只想更改输入的一个值,例如:在输入收入“ xy”中,我要更改的只是“ and”,假设新值是“ p”,而“ x”离开。 The end result should be "xp".
最终结果应为“ xp”。
http://s2.subirimagenes.com/privadas/previo/thump_2265651input.png http://s2.subirimagenes.com/privadas/previo/thump_2265653input2.png http://s2.subirimagenes.com/privadas/previo/thump_2265651input.png http://s2.subirimagenes.com/privadas/previo/thump_2265653input2.png
<input type="text"id="txtChar1" onkeypress="isNumberKey();">
function isNumberKey()
{
var text = document.getElementById(txtChar1).value;
if (text[1] >= 0)
{
text[1].write("p");
text[1].value ="p";
text.charAt(1).value = "p";
text[1].innerHTML = "p";
text[1] = "p";
}
}
Forget clarify the options that exist in this condition are those that probe and did not walk any. 忘记澄清在这种情况下存在的选项是那些探测并且没有行走的选项。
Strings are immutable. 字符串是不可变的。 Your description is unclear, but the best I can tell is that you want to reverse the order of the characters.
您的描述不清楚,但是我能告诉您的最好的一点是您想颠倒字符的顺序。
function isNumberKey()
{
var el = document.getElementById("txtChar1");
el.value = el.value.split("").reverse().join("");
}
The .split("")
converts the string into an Array of its characters. .split("")
将字符串转换为其字符数组。 Then .reverse()
reverses the order of those Array members and .join("")
joins the members back into a string. 然后,
.reverse()
反转这些Array成员的顺序,而.join("")
将成员重新组合成字符串。
Another approach would be to pass this
to the function, since that's the one getting updated. 另一种方法是
this
方法传递给函数,因为那是要更新的方法。
<input type="text"id="txtChar1" onkeypress="isNumberKey(this);">
function isNumberKey(el)
{
el.value = el.value.split("").reverse().join("");
}
I won't go into detail about what was wrong with your code, because I think you were just throwing together a bunch of arbitrary bits of code in the hope that it would work. 我不会详细介绍您的代码出了什么问题,因为我认为您只是将一堆任意的代码组合在一起,希望它能起作用。 Needless to say, it's almost all wrong.
不用说,这几乎都是错误的。
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