为什么trim（）无法与$ .each一起使用以删除字符串数组中的空格

Question

I want to use .split() to generate an array from a comma separated string, but I need to get rid of the white space.

var a = "one, two".split(",");

a  ==>  ["one", " two"]

a[1].trim() ==> "two"

$.each(a, function(i,v){v.trim()})  ==> ["one", " two"]

What am i missing about trimming whitespace from the second string in the array, and is there a better way to trim the white space from a comma separated string?

Answer 1

Your problem is that you are retrieving the value v.trim() , but doing nothing with it. Replace this portion:

$.each(a, function(i,v){v.trim()})

With this:

for(var i=0; i<a.length; i++) {
    a[i] = a[i].trim();
}

And it should work just fine.

Answer 2

Just split with a regex:

var a = "one,   two,  three  ,  four".split(/\s*,\s*/);

console.log(a); //=> ["one", "two", "three", "four"]

If you have spaces at the beginning or the end you can use trim first:

a = " one,   two,  three  ,  four  ".trim().split(/\s*,\s*/);

Answer 3

trim()将返回修剪后的字符串，但原始字符串不会被修改，因此您必须为其分配。

Answer 4

your inner function doesn't actually return a value. As others have mentioned, trim returns a copy of the string with leading and trailing whitespace removed. Also, each doesn't use the return values of the functions at all, so you can't use it to replace elements. You need

$.map(a, function(v){return v.trim();});

for this to work. (Assigning to v won't work, since v is just a local variable.)

Answer 5

If you still want to use jquery's each do it this way:

$.each(a,function(i,v){
  a[i] = v.trim();
}