Help with string operations?

Projects Programming
1

Can anyone help me with string operations?

I have a CSV string that I would like to assign string variables to different values within the string
such as:

string str1 = CSVstring[0];
string str2 = CSVstring[1];

I haven't played around with strings before and there must be some sort of string
operation commands available?

What is the best way to do this?

THANKS!

2

You may want to have a look at the text parser library.

Example:

#include <textparser.h>

TextParser parser(", ");  // Delimiter is a comma followed by a space.

If all fields are of the same type, we can use an array.

int a[5];
parser.parseLine("1, 2, 3, 4, 5", a);
// `a` now contains 1, 2, 3, 4 and 5.

If the fields have different types, we can use multiple variables.

char a[4];
int b;
double c;
parser.parseLine("one, 2, 3.4", a, b, c);
// `a` now contains "one", `b` contains 2 and `c` contains 3.4.

In your case, instead of providing a string constant, as is done in the examples above, you can provide CSVstring.c_str().

3

Do you mean "char *" when you say 'string' or do you mean "String" when you say 'string'? The coding is different for each.

4

consider

char s [80];

// -----------------------------------------------------------------------------
#define MaxTok  10
char *toks [MaxTok];
int   vals [MaxTok];

int
tokenize (
    char       *s,
    const char *sep )
{
    unsigned n = 0;
    toks [n] = strtok (s, sep);
    vals [n] = atoi (toks [n]);

    for (n = 1; (toks [n] = strtok (NULL, sep)); n++)
        vals [n] = atoi (toks [n]);

    return n;
}

// -----------------------------------------------------------------------------
void dispToks (
    char * toks [])
{
    char s [40];
    for (unsigned n = 0; toks [n]; n++)  {
        sprintf (s, " %6d  %s", vals [n], toks [n]);
        Serial.println (s);
    }
}

// -----------------------------------------------------------------------------
void loop ()
{
    if (Serial.available ())  {
        int n = Serial. readBytesUntil ('\n', s, sizeof(s)-1);
        s [n] = 0;      // terminate string

        tokenize (s, ",");
        dispToks (toks);
    }
}

// -----------------------------------------------------------------------------
void setup ()
{
    Serial.begin (9600);
}
5

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