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#1
February 25th, 2003, 03:23 PM
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string letter detection?
Is there a way that I can tell if a string has a certain letter in it? For example:
string asdfa; cout<<"type in string"; cin>>asdfa; if...(there is the letter 'a' in string) { cout << "Your string contained the letter 'a' which isn't allowed in my program"; } else if (if there isn't letter 'a' in string) { continue... } So I guess I am askign if there is a way I can detect a letter in a string and react based on if the user has typed that letter or not. Thanks! -andy
__________________
hmmm...
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#2
February 25th, 2003, 03:32 PM
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Use strchr() or strstr()
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#4
February 25th, 2003, 04:48 PM
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andy3109,
Those functions are going to implement a process whereby you examine each character in the string using array notation. Using the string length as the loop control, you can examine each character of the string like this: Code:
string text;
char looking_for = 'a';
bool found_flag = false;
for(int i=0; i<text.length(); i++)
{
if(text[i]==looking_for)
{
found_flag=true;
break;
}
}
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#5
February 25th, 2003, 06:29 PM
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Use the STL:
Code:
#include <algorithm>
std::string::size_type pos =0;
pos = asdfa.find_first_of("x", 0); // find "x"
if (pos == std::string::npos)
// nope
else
// found
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#8
February 25th, 2003, 08:48 PM
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All characters are stored as integer codes. You can look up the ASCII codes for all the characters--there's a table of codes in the appendix of my book, so check yours for the table.
ASCII codes for A-F are 65-70, so you can test whether text[i] is between 65 and 70. Last edited by 7stud : February 25th, 2003 at 08:52 PM.
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