I have
var id="ctl03_Tabs1";
Using JavaScript, how might I get the last five characters or last character?
I have
var id="ctl03_Tabs1";
Using JavaScript, how might I get the last five characters or last character?
EDIT: As others have pointed out, use slice(-5)
instead of substr
. However, see the .split().pop()
solution at the bottom of this answer for another approach.
Original answer:
You'll want to use the Javascript string method .substr()
combined with the .length
property.
var id = "ctl03_Tabs1";
var lastFive = id.substr(id.length - 5); // => "Tabs1"
var lastChar = id.substr(id.length - 1); // => "1"
This gets the characters starting at id.length - 5 and, since the second argument for .substr() is omitted, continues to the end of the string.
You can also use the .slice()
method as others have pointed out below.
If you're simply looking to find the characters after the underscore, you could use this:
var tabId = id.split("_").pop(); // => "Tabs1"
This splits the string into an array on the underscore and then "pops" the last element off the array (which is the string you want).
You can use the substr() method with a negative starting position to retrieve the last n characters. For example, this gets the last 5:
var lastFiveChars = id.substr(-5);
Getting the last character is easy, as you can treat strings as an array:
var lastChar = id[id.length - 1];
To get a section of a string, you can use the substr function or the substring function:
id.substr(id.length - 1); //get the last character
id.substr(2); //get the characters from the 3rd character on
id.substr(2, 1); //get the 3rd character
id.substr(2, 2); //get the 3rd and 4th characters
The difference between substr
and substring
is how the second (optional) parameter is treated. In substr
, it's the amount of characters from the index (the first parameter). In substring
, it's the index of where the character slicing should end.
The Substr function allows you to use a minus to get the last character.
var string = "hello";
var last = string.substr(-1);
It's very flexible. For example:
// Get 2 characters, 1 character from end
// The first part says how many characters
// to go back and the second says how many
// to go forward. If you don't say how many
// to go forward it will include everything
var string = "hello!";
var lasttwo = string.substr(-3,2);
// = "lo"
If you just want the last character or any character at know position you can simply trat string as an array! - strings are iteratorable in javascript -
Var x = "hello_world";
x[0]; //h
x[x.length-1]; //d
Yet if you need more than just one character then use splice is effective
x.slice(-5); //world
Regarding your example
"rating_element-<?php echo $id?>"
To extract id you can easily use split + pop
Id= inputId.split('rating_element-')[1];
This will return the id, or undefined if no id was after 'rating_element' :)
Today 2020.12.31 I perform tests on MacOs HighSierra 10.13.6 on Chrome v87, Safari v13.1.2 and Firefox v84 for chosen solutions for getting last N characters case (last letter case result, for clarity I present in separate answer).
For all browsers
slice
is fast or fastestI perform 2 tests cases:
Below snippet presents solutions A B C D E F G (my)
//https://stackguides.com/questions/5873810/how-can-i-get-last-characters-of-a-string
// https://stackoverflow.com/a/30916653/860099
function A(s,n) {
return s.substr(-n)
}
// https://stackoverflow.com/a/5873890/860099
function B(s,n) {
return s.substr(s.length - n)
}
// https://stackoverflow.com/a/17489443/860099
function C(s,n) {
return s.substring(s.length - n, s.length);
}
// https://stackoverflow.com/a/50395190/860099
function D(s,n) {
return s.slice(-n);
}
// https://stackoverflow.com/a/50374396/860099
function E(s,n) {
let i = s.length-n;
let r = '';
while(i<s.length) r += s.charAt(i++);
return r
}
// https://stackoverflow.com/a/17489443/860099
function F(s,n) {
let i = s.length-n;
let r = '';
while(i<s.length) r += s[i++];
return r
}
// my
function G(s,n) {
return s.match(new RegExp(".{"+n+"}$"));
}
// --------------------
// TEST
// --------------------
[A,B,C,D,E,F,G].map(f=> {
console.log(
f.name + ' ' + f('ctl03_Tabs1',5)
)})
This shippet only presents functions used in performance tests - it not perform tests itself!
And here are example results for chrome
Assuming you will compare the substring against the end of another string and use the result as a boolean you may extend the String class to accomplish this:
String.prototype.endsWith = function (substring) {
if(substring.length > this.length) return false;
return this.substr(this.length - substring.length) === substring;
};
Allowing you to do the following:
var aSentenceToPonder = "This sentence ends with toad";
var frogString = "frog";
var toadString = "toad";
aSentenceToPonder.endsWith(frogString) // false
aSentenceToPonder.endsWith(toadString) // true
To get the last character of a string, you can use the split('').pop()
function.
const myText = "The last character is J";
const lastCharater = myText.split('').pop();
console.log(lastCharater); // J
It's works because when the split('')
function has empty('') as parameter, then each character of the string is changed to an element of an array. Thereby we can use the pop()
function which returns the last element of that array, which is, the 'J' character.
Today 2020.12.31 I perform tests on MacOs HighSierra 10.13.6 on Chrome v87, Safari v13.1.2 and Firefox v84 for chosen solutions for getting last character case (last N letters case results, for clarity I present in separate answer).
For all browsers
I perform 2 tests cases:
Below snippet presents solutions A B C D E F G (my), H (my)
//https://stackguides.com/questions/5873810/how-can-i-get-last-characters-of-a-string
// https://stackoverflow.com/a/30916653/860099
function A(s) {
return s.substr(-1)
}
// https://stackoverflow.com/a/5873890/860099
function B(s) {
return s.substr(s.length - 1)
}
// https://stackoverflow.com/a/17489443/860099
function C(s) {
return s.substring(s.length - 1, s.length);
}
// https://stackoverflow.com/a/50395190/860099
function D(s) {
return s.slice(-1);
}
// https://stackoverflow.com/a/50374396/860099
function E(s) {
return s.charAt(s.length-1);
}
// https://stackoverflow.com/a/17489443/860099
function F(s) {
return s[s.length-1];
}
// my
function G(s) {
return s.match(/.$/);
}
// my
function H(s) {
return [...s].pop();
}
// --------------------
// TEST
// --------------------
[A,B,C,D,E,F,G,H].map(f=> {
console.log(
f.name + ' ' + f('ctl03_Tabs1')
)})
This shippet only presents functions used in performance tests - it not perform tests itself!
And here are example results for chrome
I actually have the following problem and this how i solved it by the help of above answer but different approach in extracting id form a an input element.
I have attached input filed with an
id="rating_element-<?php echo $id?>"
And , when that button clicked i want to extract the id(which is the number) or the php ID ($id) only.
So here what i do .
$('.rating').on('rating.change', function() {
alert($(this).val());
// console.log(this.id);
var static_id_text=("rating_element-").length;
var product_id = this.id.slice(static_id_text); //get the length in order to deduct from the whole string
console.log(product_id );//outputs the last id appended
});
const id = 'ctl03_Tabs1';
id.at(-1); // Returns '1'
at
supports negative integer to count back from the last string character.
Docs: String/at
Note: Experimental feature! Support will land in Chrome v90.