| .Selected String Manipulation Example Programs. |
|
 Selected Programs String Manipulation Contents Index |
| ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ |
| String Manipulation Programs |
| |
| The following programming examples demonstrate various ways to manipulate |
| sequences of ASCII characters known as strings. |
| |
| Example 1 |
| |
| One of the most common string-processing tasks is searching for a string |
| inside another string. The INSTR function tells you whether or not |
| string2 is contained in string1 by returning the position of the first |
| character in string1 (if any) where the match begins. If no match is |
| found (that is, string2 is not a substring of string1, INSTR returns |
| the value 0. |
| |
| The following programming example demonstrates this: |
| |
| String1$ = "A line of text with 37 letters in it." |
| String2$ = "letters" |
| PRINT " 1 2 3 4" |
| PRINT "1234567890123456789012345678901234567890" |
| PRINT String1$ |
| PRINT String2$ |
| PRINT INSTR(String1$, String2$) |
| |
| Sample output |
| |
| 1 2 3 4 |
| 1234567890123456789012345678901234567890 |
| A line of text with 37 letters in it. |
| letters |
| 24 |
| |
| Example 2 |
| |
| The INSTR(position, string1, string2) variation is useful for finding |
| every occurrence of string2 in string1, instead of just the first |
| occurrence of string2 in string1, as shown in the next example: |
| |
| String1$ = "the quick basic jumped over the broken saxophone." |
| String2$ = "the" |
| PRINT String1$ |
| Start = 1 |
| NumMatches = 0 |
| DO |
| Match = INSTR(Start, String1$, String2$) |
| IF Match > 0 THEN |
| PRINT TAB(Match); String2$ |
| Start = Match + 1 |
| NumMatches = NumMatches + 1 |
| END IF |
| LOOP WHILE MATCH |
| PRINT "Number of matches ="; NumMatches |
| |
| Sample output |
| |
| the quick basic jumped over the broken saxophone. |
| the |
| the |
| Number of matches = 2 |
