First I set a variable, and set it to empty:
var str = "";
Then I split it through "&":
var strs = str.split('&');
In the end, I show strs's length:
alert( strs.length);
It alert "1".
But I assign nothing to the 'str' variable. Why does it still have a length, should't it be zero?
From the MDC doc center:
Note: When the string is empty,
splitreturns an array containing one empty string, rather than an empty array.
Read the full docs here: https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/String/split
In other words, this is by design, and not an error :)
'&'.split('&') returns 2 empty strings; '&&'.split('&') returns 3; etc.
"One\n\nThree".split('\n') which is ["One","","Three"]. Notice that the second line is blank (""). If the text file has only one line, "One".split('\n') the result is ["One"]. So logically, "".split('\n') should be [""] since there is still one line. The line is blank, but we saw before that a blank line is "". In some languages such as C# there is an option to remove empty entries from the output, but JavaScript does not offer it.
str.split('&').filter(o=>o) which would eliminate any empty string in the array and in your case, it would return an empty array!Splitting window.location.pathname
Note that on window.location.pathname splitting it will mostly return a length of +1 also.
Lets assume our pathname in this case is: /index.html.
var str = window.location.pathname.split('/');
It will be split into ["" , "index.html"] by design, as mentioned here many times before.
What one could do in this case is, strip the leading and trailing / like so:
var str = window.location.pathname.replace(/^\/|\/$/g, '').split('/');
and end up with the "correct"ed length.
Because you get an array that contains the empty string:
[ "" ]
That empty string is one element. So length is 1.
Eliminate any null string.
str.split('{SEPERATOR}').filter(r => r !== 'null')
filter(r => r) // Empty string, undefined, null, ...Description
The split method returns the new array.
When found, separator is removed from the string and the substrings are returned in an array. If separator is omitted, the array contains one element consisting of the entire string.
Note: When the string is empty, split returns an array containing one empty string, rather than an empty array.
https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/String/split
I got sick of always checking for a[0] == '' so:
String.prototype.splitPlus = function(sep) {
var a = this.split(sep)
if (a[0] == '') return [];
return a;
};
Corrected version for when element 1 might be null:
String.prototype.splitPlus = function(sep) {
var a = this.split(sep)
if (a[0] == '' && a.length == 1) return [];
return a;
};
if (a[0] == '' && a.length == 1) return [];
===? .JavaScript split creates an array. That is, your variable, strs = [0]=>"" and its length is 1.
invent explode/implode (like PHP)
Object.defineProperty(String.prototype,"explode",{
value: function (sep = '') {
return this.length ? this.split(sep) : [];
}
});
so empty-string goes to empty-array
try this
javascript gives two arrays by split function, then
var Val = "[email protected]";
var mail = Val.split('@');
if(mail[0] && mail[1]) { alert('valid'); }
else { alert('Enter valid email id'); valid=0; }
if both array contains length greater than 0 then condition will true
.split('...').filter(Boolean)if you didnt care about falsy values.