MbStringLength

[a] → [String(a).length]

• Action Code: 0x31
• Stack: 1 → 1
• SWF version: 4

Adobe documentation

ActionMBStringLength

ActionMBStringLength computes the length of a string and is multi-byte aware.

Field	Type	Comment
ActionMBStringLength	ACTIONRECORDHEADER	ActionCode = 0x31

ActionMBStringLength does the following:

1. Pops a string off the stack.
2. Calculates the length of the string in characters and pushes it to the stack.

This is a multi-byte aware version of ActionStringLength. On systems with double-byte support, a double-byte character is counted as a single character.