KB-2372 Known unexpected behaviour of left() and leftb() functions

pauline.delacruz — Tue, 17 Mar 2026 15:42:17 GMT

Current Revision posted to Appian Knowledge Base by pauline.delacruz on 3/17/2026 3:42:17 PM

Purpose

The purpose of this article is to demonstrate the current unexpected behavior of the functions left(), len(), lenb() and leftb().

Symptoms

When using left(), leftb(), len() and lenb(), there is unexpected behavior in how these functions count certain characters, such as emojis.

Cause

The following results demonstrate that currently left() and leftb() do not provide the expected outputs based on their function documentation:

len() counts an emoji as 1 character (expected)
lenb() counts an emoji as 4 bytes (expected)
left() counts an emoji as 2 characters (unexpected, expected 1)
leftb() counts an emoji as 2 bytes (unexpected, expected be 4)
left and leftb() always ouput the same result (2 in this case)

As a result of this inconsistency, it is not possible to truncate a length of text to a specific number of bytes.

Workaround

Check the string’s byte length using lenb(ri!text). If it's within the limit, return the string.
If it exceeds the limit, use regexfirstmatch() to trim one character at a time.
Repeat step 2 until the byte length is within the limit.

Note: This method fails if more than 529 characters need to be removed (due to recursion limits). Emoji-heavy messages are more likely to cause this issue.

Affected Versions

This article applies to all versions of Appian.

Last Reviewed: March 2026

Tags: integration

KB-2372 Known unexpected behaviour of left() and leftb() functions

pauline.delacruz — Tue, 17 Mar 2026 15:42:17 GMT

Revision 10 posted to Appian Knowledge Base by pauline.delacruz on 3/17/2026 3:42:17 PM

Purpose

The purpose of this article is to demonstrate the current unexpected behavior of the functions left(), len(), lenb() and leftb().

Symptoms

When using left(), leftb(), len() and lenb(), there is unexpected behavior in how these functions count certain characters, such as emojis.

Cause

The following results demonstrate that currently left() and leftb() do not provide the expected outputs based on their function documentation:

len() counts an emoji as 1 character (expected)
lenb() counts an emoji as 4 bytes (expected)
left() counts an emoji as 2 characters (unexpected, expected 1)
leftb() counts an emoji as 2 bytes (unexpected, expected be 4)
left and leftb() always ouput the same result (2 in this case)

As a result of this inconsistency, it is not possible to truncate a length of text to a specific number of bytes.

Workaround

Check the string’s byte length using lenb(ri!text). If it's within the limit, return the string.
If it exceeds the limit, use regexfirstmatch() to trim one character at a time.
Repeat step 2 until the byte length is within the limit.

Note: This method fails if more than 529 characters need to be removed (due to recursion limits). Emoji-heavy messages are more likely to cause this issue.

Affected Versions

This article applies to all versions of Appian.

Last Reviewed: March 2026

Tags: integration

[DRAFT SUPP-1053] KB-XXXX Known unexpected behaviour of left() and leftb() functions

pauline.delacruz — Wed, 14 May 2025 21:06:06 GMT

Revision 9 posted to Appian Knowledge Base by pauline.delacruz on 5/14/2025 9:06:06 PM

Purpose

The purpose of this article is to demonstrate the current unexpected behavior of the functions left(), len(), lenb() and leftb().

Symptoms

When using left(), leftb(), len() and lenb(), there is unexpected behavior in how these functions count certain characters, such as emojis.

Cause

The following results demonstrate that currently left() and leftb() do not provide the expected outputs based on their function documentation:

len() counts an emoji as 1 character (expected)
lenb() counts an emoji as 4 bytes (expected)
left() counts an emoji as 2 characters (unexpected, expected 1)
leftb() counts an emoji as 2 bytes (unexpected, expected be 4)
left and leftb() always ouput the same result (2 in this case)

Because of this inconsistency, it is not possible to truncate a length of text to a specific number of bytes.

Workaround

Check the string’s byte length using lenb(ri!text). If it's within the limit, return the string.
If it exceeds the limit, use regexfirstmatch() to trim one character at a time.
Repeat step 2 until the byte length is within the limit.

Note: This method fails if more than 529 characters need to be removed (due to recursion limits). Emoji-heavy messages are more likely to cause this issue.

Affected Versions

This article applies to all versions of Appian.

Last Reviewed: May 2025

[DRAFT SUPP-1053] KB-XXXX Known unexpected behaviour of left() and leftb() functions

pauline.delacruz — Wed, 14 May 2025 21:03:19 GMT

Revision 8 posted to Appian Knowledge Base by pauline.delacruz on 5/14/2025 9:03:19 PM

Purpose

The purpose of this article is to demonstrate the current unexpected behavior of the functions left(), len(), lenb() and leftb().

left(), leftb(), len() and lenb()

Symptoms

When using left(), leftb(), len() and lenb(), there is unexpected behavior in how these functions count certain characters, such as emojis.

Cause

The following results demonstrate that currently left() and leftb() do not provide the expected outputs based on their function documentation:

len() counts an emoji as 1 character (expected)
lenb() counts an emoji as 4 bytes (expected)
left() counts an emoji as 2 characters (unexpected, expected 1)
leftb() counts an emoji as 2 bytes (unexpected, expected be 4)
left and leftb() always ouput the same result (2 in this case)

Because of this inconsistency, it is not possible to truncate a length of text to a specific number of bytes.

Workaround

Check the string’s byte length using lenb(ri!text). If it's within the limit, return the string.
If it exceeds the limit, use regexfirstmatch() to trim one character at a time.
Repeat step 2 until the byte length is within the limit.

Note: This method fails if more than 529 characters need to be removed (due to recursion limits). Emoji-heavy messages are more likely to cause this issue.

Affected Versions

This article applies to all versions of Appian.

Last Reviewed: May 2025

[DRAFT SUPP-1053] KB-XXXX Known unexpected behaviour of left() and leftb() functions

pauline.delacruz — Wed, 14 May 2025 21:02:07 GMT

Revision 7 posted to Appian Knowledge Base by pauline.delacruz on 5/14/2025 9:02:07 PM

Purpose

The purpose of this article is to demonstrate the current unexpected behavior of the functions left(), len(), lenb() and leftb().

Symptoms

When using left(), leftb(), len() and lenb(), there is unexpected behavior in how these functions count certain characters, such as emojis.

Cause

The following results demonstrate that currently left() and leftb() do not provide the expected outputs based on their function documentation:

len() counts an emoji as 1 character (expected)
lenb() counts an emoji as 4 bytes (expected)
left() counts an emoji as 2 characters (unexpected, expected 1)
leftb() counts an emoji as 2 bytes (unexpected, expected be 4)
left and leftb() always ouput the same result (2 in this case)

Because of this inconsistency, it is not possible to truncate a length of text to a specific number of bytes.

Workaround

Check the string’s byte length using lenb(ri!text). If it's within the limit, return the string.
If it exceeds the limit, use regexfirstmatch() to trim one character at a time.
Repeat step 2 until the byte length is within the limit.

Note: This method fails if more than 529 characters need to be removed (due to recursion limits). Emoji-heavy messages are more likely to cause this issue.

Affected Versions

This article applies to all versions of Appian.

Last Reviewed: May 2025

[DRAFT SUPP-1053] KB-XXXX Known unexpected behaviour of left() and leftb() functions

pauline.delacruz — Wed, 14 May 2025 21:01:13 GMT

Revision 6 posted to Appian Knowledge Base by pauline.delacruz on 5/14/2025 9:01:13 PM

Purpose

The purpose of this article is to demonstrate the current unexpected behavior of the functions left(), len(), lenb() and leftb().

Symptoms

When using left(), leftb(), len() and lenb(), there is unexpected behavior in how these functions count certain characters, such as emojis.

Cause

The following results demonstrate that currently left() and leftb() do not provide the expected outputs based on their function documentation:

len() counts an emoji as 1 character (expected)
lenb() counts an emoji as 4 bytes (expected)
left() counts an emoji as 2 characters (unexpected, expected 1)
leftb() counts an emoji as 2 bytes (unexpected, expected be 4)
left and leftb() always ouput the same result (2 in this case)

Because of this inconsistency, it is not possible to truncate a length of text to a specific number of bytes.

Workaround

Check the string’s byte length using lenb(ri!text). If it's within the limit, return the string.
If it exceeds the limit, use regexfirstmatch() to trim one character at a time.
Repeat step 2 until the byte length is within the limit.

Note: This method fails if more than 529 characters need to be removed (due to recursion limits). Emoji-heavy messages are more likely to cause this issue.

Affected Versions

This article applies to all versions of Appian.

Last Reviewed: May 2025

[DRAFT SUPP-1053] KB-XXXX Known unexpected behaviour of left() and leftb() functions

pauline.delacruz — Wed, 14 May 2025 20:59:44 GMT

Revision 5 posted to Appian Knowledge Base by pauline.delacruz on 5/14/2025 8:59:44 PM

Purpose

The purpose of this article is to demonstrate the current unexpected behavior of the functions left(), len(), lenb() and leftb().

Symptoms

When using left(), leftb(), len() and lenb(), there is unexpected behavior in how these functions count certain characters, such as emojis.

Cause

The following results demonstrate that currently left() and leftb() do not provide the expected outputs based on their function documentation:

len() counts an emoji as 1 character (expected)
lenb() counts an emoji as 4 bytes (expected)
left() counts an emoji as 2 characters (unexpected, expected 1)
leftb() counts an emoji as 2 bytes (unexpected, expected be 4)
left and leftb() always ouput the same result (2 in this case)

Because of this inconsistency, it is not possible to truncate a length of text to a specific number of bytes.

Workaround

Check the string’s byte length using lenb(ri!text). If it's within the limit, return the string.
If it exceeds the limit, use regexfirstmatch() to trim one character at a time.
Repeat step 2 until the byte length is within the limit.

Limitations: This method fails if more than 529 characters need to be removed (due to recursion limits). Emoji-heavy messages are more likely to cause this issue.

Affected Versions

This article applies to all versions of Appian.

Last Reviewed: May 2025

[DRAFT SUPP-1053] KB-XXXX Known unexpected behaviour of left() and leftb() functions

pauline.delacruz — Tue, 13 May 2025 21:44:29 GMT

Revision 4 posted to Appian Knowledge Base by pauline.delacruz on 5/13/2025 9:44:29 PM

Purpose

The purpose of this article is to demonstrate the current unexpected behavior of the functions left(), len(), lenb() and leftb().

Symptoms

When using left(), leftb(), len() and lenb(), there is unexpected behavior in how these functions count certain characters, such as emojis.

Cause

The following results demonstrate that currently left() and leftb() do not provide the expected outputs based on their function documentation:

len() counts an emoji as 1 character (expected)
lenb() counts an emoji as 4 bytes (expected)
left() counts an emoji as 2 characters (unexpected, expected 1)
leftb() counts an emoji as 2 bytes (unexpected, expected be 4)
left and leftb() always ouput the same result (2 in this case)

Because of this inconsistency, it is not possible to truncate a length of text to a specific number of bytes.

Workaround

Check the string’s byte length using lenb(ri!text). If it's within the limit, return the string.
If it exceeds the limit, use regexfirstmatch() to trim one character at a time.
Repeat step 2 until the byte length is within the limit.

Limitations: This method fails if more than 529 characters need to be removed (due to recursion limits). Emoji-heavy messages are more likely to cause this issue.

Affected Versions

This article applies to all versions of Appian.

Last Reviewed: May 2025

[DRAFT SUPP-1053] KB-XXXX Known unexpected behaviour of left() and leftb() functions

pauline.delacruz — Tue, 13 May 2025 21:44:00 GMT

Revision 3 posted to Appian Knowledge Base by pauline.delacruz on 5/13/2025 9:44:00 PM

Purpose

The purpose of this article is to demonstrate the current unexpected behavior of the functions left(), len(), lenb() and leftb().

Symptoms

When using left(), leftb(), len() and lenb(), there is unexpected behavior in how these functions count certain characters, such as emojis.

The following results demonstrate that currently left() and leftb() do not provide the expected outputs based on their function documentation:

len() counts an emoji as 1 character (expected)
lenb() counts an emoji as 4 bytes (expected)
left() counts an emoji as 2 characters (unexpected, expected 1)
leftb() counts an emoji as 2 bytes (unexpected, expected be 4)
left and leftb() always ouput the same result (2 in this case)

Because of this inconsistency, it is not possible to truncate a length of text to a specific number of bytes.

Workaround

Check the string’s byte length using lenb(ri!text). If it's within the limit, return the string.
If it exceeds the limit, use regexfirstmatch() to trim one character at a time.
Repeat step 2 until the byte length is within the limit.

Limitations: This method fails if more than 529 characters need to be removed (due to recursion limits). Emoji-heavy messages are more likely to cause this issue.

Affected Versions

This article applies to all versions of Appian.

Last Reviewed: May 2025

[DRAFT SUPP-1053] KB-XXXX Known unexpected behaviour of left() and leftb() functions

pauline.delacruz — Tue, 13 May 2025 21:39:20 GMT

Revision 2 posted to Appian Knowledge Base by pauline.delacruz on 5/13/2025 9:39:20 PM

Purpose

The purpose of this article is to demonstrate the current unexpected behaviour of left() and leftb().

Symptoms

When using left(), leftb(), len() and lenb(), there is unexpected behavior in how these functions count certain characters, (such as emojis).

The following results demonstrate that currently left() and leftb() do not provide the expected outputs based on their function documentation:

len() counts an emoji as 1 character (expected)
lenb() counts an emoji as 4 bytes (expected)
left() counts an emoji as 2 characters (unexpected, expected 1)
leftb() counts an emoji as 2 bytes (unexpected, expected be 4)
left and leftb() always ouput the same result (2 in this case)

Because of this inconsistency, it is not possible to truncate a length of text to a specific number of bytes.

Workaround

Check the string’s byte length using lenb(ri!text). If it's within the limit, return the string.
If it exceeds the limit, use regexfirstmatch() to trim one character at a time.
Repeat step 2 until the byte length is within the limit.

Limitations: This method fails if more than 529 characters need to be removed (due to recursion limits). Emoji-heavy messages are more likely to cause this issue.

Affected Versions

This article applies to all versions of Appian.

Last Reviewed: May 2025

[DRAFT SUPP-1053] KB-XXXX Known unexpected behaviour of left() and leftb() functions

pauline.delacruz — Tue, 13 May 2025 21:34:39 GMT

Revision 1 posted to Appian Knowledge Base by pauline.delacruz on 5/13/2025 9:34:39 PM

Purpose

The purpose of this article is to demonstrate the current unexpected behaviour of left() and leftb().

Symptoms

When using left(), leftb(), len() and lenb(), there is unexpected behaviour in how these functions count certain characters, (such as emojis).

The Following results demonstrate that currently left() and leftb() do not provide the expected outputs based on their function documentation:

len() counts an emoji as 1 character (expected)
lenb() counts an emoji as 4 bytes (expected)
left() counts an emoji as 2 characters (unexpected, expected 1)
leftb() counts an emoji as 2 bytes (unexpected, expected be 4)
left and leftb() always ouput the same result (2 in this case)

Because of this inconsistency, it is not possible to truncate a length of text to a specific number of bytes.

Workaround

Check the string’s byte length using lenb(ri!text). If it's within the limit, return the string.
If it exceeds the limit, use regexfirstmatch() to trim one character at a time.
Repeat step 2 until the byte length is within the limit.

Limitations: This method fails if more than 529 characters need to be removed (due to recursion limits). Emoji-heavy messages are more likely to cause this issue.

Affected Versions

This article applies to all versions of Appian.

Last Reviewed: May 2025