JavaScript Remove Last Character from String: 6 Easy Tips!

JavaScript Remove Last Character from String is not as an easy task as you think. There are a lot of considerations that you have to think about before applying the logic. From user input to data processing or string manipulation, you need to apply different tricks for different cases.

There are a lot of edge cases that require additional attention from you. Such a last character can be a space, a new line, or even a special character. Unicode considerations are also needed. So for every scenario, every approach may not work. You have to handle each scenario very carefully.

In this post, we are going to resolve all issues that you can face while implementing “javascript remove last character from string.” So without wasting any time, let’s dive into it.

No. 1: Using Slice Method

The JS slice() method of String is used to get a portion of a supplid string and return the newly selected portion of the string as a new string. The slice() method does not modify the original string, as strings in JavaScript are immutable.

You can specify a start and end index to select a certain portion of the supplied string; even you can use a negative index to tell the JS to start counting from the end of the string, not from the first of the string. This negative input makes this method an ideal option to remove the last character of a string.

Syntax

slice(indexStart)
slice(indexStart, indexEnd)

Code Example to Understand the Slice() Method Better

<script>

   // Using Slice() method with postive indexes   

   var str1 = "JavaScript Remove Last Character from String: 10 Easy Tips!"; 
   // The length of var str1 is 59.
   
   console.log(str1.slice(0, 10)); // JavaScript
   console.log(str1.slice(4, 10)); // Script
   console.log(str1.slice(11)); // Remove Last Character from String: 10 Easy Tips!
   console.log(str1.slice(60)); // "" As index no > length

   // Using Slice() method with negetive indexes

   console.log(str1.slice(-5)); // Tips!
   console.log(str1.slice(-5,-1)); // Tips
   console.log(str1.slice(0,-1));  // JavaScript Remove Last Character from String: 10 Easy Tips
   console.log(str1); // JavaScript Remove Last Character from String: 10 Easy Tips!

</script>

Output

Code Explanation

Here slice(0, -1) removes the last character of the str1 string because -1 always means the last index of the string. This slice operation does not affect the variable str1. See the last line of output.

JS Slice() Method 6 Points to Remember

1. If startIndex >= length, then it returns an empty string.
2. If startIndex < 0, then it counts the index from the last of the string, not from the first of the string.
3. If startIndex is not provided, undefined, or not a valid number, then it is considered 0.
4. If endIndex is not provided, undefined, or not a valid number, or if endIndex >= length, slice() considers the end of the string.
5. If endIndex < 0, the index is counted from the end of the string.
6. If endIndex <= startIndex, then it returns an empty string, like startIndex >= length.

No. 2: Using Substring Method

The JSsubstring() method is used to return a part of the string from a valid start index up to the end index. Like the slice() method, it returns a new string without changing the original string.

Syntax

substring(indexStart)
substring(indexStart, indexEnd)

Code Example

<script>

   // Using substring() method

   var str1 = "JavaScript Remove Last Character from String: 10 Easy Tips!"; 
   // The length of var str1 is 59.
   
   console.log(str1.substring(0, str1.length-1)); // JavaScript Remove Last Character from String: 10 Easy Tips
   // Length=59, so endIndex=59-1=58

   console.log(str1.substring(0, 58)); // JavaScript Remove Last Character from String: 10 Easy Tips
   // Length=59, so endIndex=59-1=58

   // Both return same. Last one is for understanding.
   // use length for creating generic methods

</script>

Code Explanation

The substring(0,str1.length-1) method removes the last character ‘!’ because str1.length-1 is the last index of the string. You cannot use negative indexes in the JS substring() method, like in the Slice() method.

One More Example to Understand substring Method Better

<script>

   // Using substring() method

   var str1 = "JavaScript Remove Last Character from String: 10 Easy Tips!"; 
   // The length of var str1 is 59.
   
   console.log(str1.substring(0, 10)); // JavaScript
   
   // Look - here startIndex > endIndex
   console.log(str1.substring(10, 0)); // JavaScript

   // Select the first character of the string
   console.log(str1.substring(0, 1)); // J

   // Alternatively Select the first character of the string
   console.log(str1.substring(1, 0)); // J

   // Not mention the lastIndex - Hence consider full length
   // Like slice() method
   console.log(str1.substring(11)); // Remove Last Character from String: 10 Easy Tips!

   // startIndex < 0 denotes to 0
   // endIndex > length dentes to length
   console.log(str1.substring(-1,60));
   // Output: JavaScript Remove Last Character from String: 10 Easy Tips!

</script>

Output

JS substring() Method 6 Points to Remember

1. If endIndex is not mentioned, substring() considers characters up to the end of the string.
2. If startIndex is equal to endIndex, substring() will always return an empty string.
3. If startIndex is greater than endIndex, then substring() will automatically reverse the argument order.
4. If startIndex < 0, then substring() considers the startIndex = 0.
5. If endIndex > length, then substring() considers endIndex = length.
6. If startIndex or endIndex is NaN, then substring() considers 0 always.

No. 3: Using Substr Method

The JavaScript substr() method is almost similar to the JS substring() method. The substr() method is deprecated now. Thus, we are not going to explain it deeply. Just for your knowledge, you can remove the last character from the string in the following way:

Code Example

<script>

   // Using substr() method

   var str1 = "JavaScript Remove Last Character from String: 10 Easy Tips!"; 
   // The length of var str1 is 59.
   
   console.log(str1.substr(0, str1.length-1)); 
   // Output: JavaScript Remove Last Character from String: 10 Easy Tips
   
</script>

No. 4: Using Replace Method

Another method that you can use to remove the last character from a string in JavaScript is the replace() method. The replace() method uses a pattern to replace a part of the string. Here, our consideration is the last character only, and we are going to use a regular expression as the last character can be anything from a number to an alpha.

Code Example

<script>

   // Using replace() method
   
   var str1 = "JavaScript Remove Last Character from String: 10 Easy Tips!"; 
   var str2 = "JavaScript Remove Last Character from String: 10 Easy Tips1"; 
   var str3 = "JavaScript Remove Last Character from String: 10 Easy Tips#"; 
   var str4 = "JavaScript Remove Last Character from String: 10 Easy Tips\n"; 
   // The length of var str1 is 59.
   
   console.log(str1.replace(/.$/, ""));
   
   // Remove number
   console.log(str2.replace(/.$/, ""));
   
   // Remove special character
   console.log(str3.replace(/.$/, "")); 

   // Remove new line
   console.log(str4.replace(/.$/, "")); 
   // Output: JavaScript Remove Last Character from String: 10 Easy Tips
   
</script>

Code Explanation

The /$/ means the end of the string, and the “.” means any character (numeric or alpha). This ‘’ means an empty string. So, the replace() method will take the variable str1 and replace the last character with an empty string. So you get your desired string without the last character.

No. 5: Using split() and join() Method

In this combined approach, first we will split the string using the JS split() method, then we will use the JS pop() method, and lastly, we will use the join() method to join the array back.

Code Example

<script>

   // Using split() and join() method
   
   var str1 = "JavaScript Remove Last Character from String: 10 Easy Tips!"; 
   let splitStr1 = str1.split('')
   splitStr1.pop();
   console.log(splitStr1.join(''));
   // Output: JavaScript Remove Last Character from String: 10 Easy Tips

</script>

Code Explanation

The JS pop() method removes the last element of an array and returns this element to the caller. This method changes the length of the array.

No. 6: Using for Loop

In this method, we will iterate over all the characters in the string except the last one. Copy all those characters that we read through the loop into a new variable. Now, the new variable does not contain the last character.

Code Example

<script>

   // Using manual loop method
   
   var str1 = "JavaScript Remove Last Character from String: 10 Easy Tips!"; 
   var str2="";

   for (let i = 0; i < str1.length-1; i++) {
        str2 += str1[i];
    }
   
   console.log(str2);
   // Output: JavaScript Remove Last Character from String: 10 Easy Tips

</script>

Performance

Considering all the above methods, we strongly recommend using the JS built-in slice(0,-1) method for removing the last character of a string. This method is the fastest solution for short and long strings, even considering a cross-browser solution.

You can also choose the substring method, as this method performed well, just lags a bit compared to the slice() method.

Regular expressions using the replace() method perform slower than the slice() and substring() methods.

See the example.

Differences Between substring() and slice() Method

Now it’s time to know the difference between substring() and slice() to master your JavaScript knowledge.

The substring() and slice() methods are almost the same, except for some differences, like the way both methods handle negative value arguments.

Slice() Method	Substring() Method
If the start index is greater than the end index, then the slice() method returns an empty string.	If the start index is greater than the end index, then the substring() method swaps the arguments.
The slice() method treats a negative argument as an indicator to start counting from last.	The substring() method treats negative arguments as 0.
slice() treats NaN arguments as 0.	substring() also treats NaN arguments as 0.

Differences Between substring() and substr() Method

Though the substr() method is deprecated now and not recommended to use this method for modern browsers. But considering legacy code you have to know the both methods equally.

Substr() Method	Substring() Method
Substr() method two parameters are strat and length.	Substring() method two parametrs are startIndex and endIndex.
If the substr() method startIndex is negative than it’s do not consider it 0 rather wrap to the end of the string.	If startIndex is a negative number then this method consider it as 0.
subStr() method considers negative lengths as 0.	In this case substring() method swap both arguments automatically

8 Use Cases of JavaScript Remove Last Character from String

Here we have discussed 8 cases where a developer need to consider removing the last character of a string:

1. Fixing a JSON parser error: Remove a trailing comma from a string.
2. URL Cleaning: Remove a trailing slash from a URL.
3. Handling User Input: such as trimming an accidental last character by a rich text editor.
4. File Processing: Remove \n or \r or both while reading data from files.
5. Trimming Data from APIs: Remove additional characters returned by API responses.
6. Trimming Custom Delimiters: Remove custom delimiters from dynamically generated strings.
7. Removing Escape Characters: Remove unnecessary trailing escape characters from a string.
8. Sanitizing Strings: Remove a trailing single quote or double quote to prevent SQL injection attacks.

Conclusion

In this post, you have learned a lot about how to remove the last character from a string in JavaScript, using 8 methods and so many example scenarios.

We have also discussed how to remove a trailing comma from a string, how to remove \n, \r, or \n\r combinedly from a string, how to remove the last multiple or consecutive characters from a string, how to remove the last special character from a string, and how to remove the last specific character from a string, numeric or alpha, whatever it is.

We have also discussed method performance. When should I use which method? Split, substring, or regular expressions.

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FAQs – JavaScript Remove Last Character from String