<!DOCTYPE html>
<html>
<body>
<p id="demo">Click the button to locate where in the string a specifed value occurs.</p>
<button onclick="myFunction()">Try it</button>
<script>
function myFunction()
{
var a =" picture";
a.replace(" ","");
var n=a.indexOf(" ");
document.getElementById("demo").innerHTML= n+a+n;
}
</script>
</body>
</html>
我想将上面示例中的“图片”中的“”（空格）替换掉
但结果似乎它没有被替换命令替换。
替换后的结果应该是“-1picture-1”，但它是“0 picture0”
图片前面有一个空格。（我使用 .indexOf(" ") 来表示
变量中是否有空格 -1 表示没有）
这是怎么回事？？请指教
replace doesn't modify the string in place, it returns a modified string.
a = a.replace(" ","");
Use String.trim() to remove trailing spaces.
https://developer.mozilla.org/en-US/docs/JavaScript/Reference/Global_Objects/String/Trim
In your example,
var a = " picture";
a = a.trim();
...
You need to assign the returned value back to a
var a =" picture";
a = a.replace(" ","");
edit:
Would also like to throw it out there that a .replace(" ","") will only work for the first instance of a space, and it may not even be at the beginning of the string. If you are wanting to trim only leading and trailing spaces, consider this:
var a =" picture";
a = a.replace(/^\s+|\s+$/g,"");
我认为这可以很好地工作......
return str.replace(/\s+/g, '');
为什么我投了反对票？？？
alert("some #$%%&& person gave me a downvote!!".replace(/\s+/g, ''));
这完全有效！！！！！！！