LEFT$ |
left$ is used to extract a sub-string from the leftmost end (from the start) of a character string.
left$( string, nb_char )
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Element |
Description |
Restrictions |
|
string |
Alphanumeric expression. |
None. |
|
nb_char |
Numerical integer expression for the length of string to be extracted. |
nb_char >= 0 |
# Extraction of the first 5 letters of the alphabet. # This programme displays "ABCDE" ALPHABET = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"Infbox left$(ALPHABET, 5)
# Calculation of the length of a character string CHAINE;
# (it is simpler to use the len function) I = 0While left$(CHAINE,I) <> CHAINE :# as long as equality is not
I += 1 :# found, increment I Wend Infbox "The length of the string "-CHAINE-" is" num$(I)# When CHAINE is "ABCDEFG", the programme displays:
# The length of the string "ABCDEFG" is 7 # To display a string, cutting it to 32 characters. # This works even if len(CHAINE) < 32Infbox left$(CHAINE, 32)
The function left$(string, nb_char) extracts the first nb_char characters from the string.
The result is a Char type.
If nb_char is 0, left$(string, nb_char) is equal to the empty string "".
If nb_char is greater than the length of the string, left$(string, nb_char) returns the whole string, without generating an error.
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Error |
Description |
|
ERMODE (10) |
string is not a Char type or nb_char is not numerical. |
|
ERDOM (50) |
nb_char < 0 |
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