String Functions with Pointers
char orgName[100] = “The Dept. of Redundancy Dept.”;
char newText[100];
char* subString = nullptr;
| strchr() | strchr(sourceStr, searchChar) Returns null pointer if searchChar does not exist in sourceStr. Else, returns pointer to first occurrence. if (strchr(orgName, 'D') != nullptr) { // 'D' exists in orgName? subString = strchr(orgName, 'D'); // Points to first 'D' strcpy(newText, subString); // newText now "Dept. of Redundancy Dept." } if (strchr(orgName, 'Z') != nullptr) { // 'Z' exists in orgName? ... // Doesn't exist, branch not taken } |
| strrchr() | strrchr(sourceStr, searchChar) Returns null pointer if searchChar does not exist in sourceStr. Else, returns pointer to LAST occurrence (searches in reverse, hence middle 'r' in name). if (strrchr(orgName, 'D') != nullptr) { // 'D' exists in orgName? subString = strrchr(orgName, 'D'); // Points to last 'D' strcpy(newText, subString); // newText now "Dept." } |
| strstr() | strstr(str1, str2) Returns char* pointing to first occurrence of string str2 within string str1. Returns null pointer if not found. subString = strstr(orgName, "Dept"); // Points to first 'D' if (subString != nullptr) { strcpy(newText, subString); // newText now "Dept. of Redundancy Dept." } |