#include<iostream> #include<string> int main() { std::string greeting ="hello "; //greeting is an object of class string. std::cout<<greeting[0]<<std::endl; //default value for string is empty string; using std::string; using std::cout; using std::endl; string name; cout<<name<<endl; //empty string is "", with nothing in between. //we can add strings; name=greeting+"vishal rao"; cout<<name<<endl; //we can also append to string; name+='!'; cout<<name<<endl; //length will provide length of string, here function is called as if name is object of class string //and lenght is function for whole class. cout<<name.length()<<endl; char new_name[]="virat kohli"; //now since new_name has assigned memory of 11 characters, we can't store larger/smaller string in here, and that is the limitation of this method. //whereas we can use string class in more flexible way. /*How to take input as string. string var; cout<<"Enter some string with space"; std::cin>>var; cout<<var<<endl;//note that cin only catches the first word, it does not catche //only first word gets stored in string. string left_over; std::cin>>left_over; cout<<left_over<<endl; //this will automatically grab the second word which was left over. */ // to get the whole sentence, we use the function getline(); string line1; cout<<"enter some sentence:"<<endl; getline(std::cin,line1); cout<<line1<<endl; /*string methods or Member functions: 1.string_obj.length() 2.string_obj.size() modifier methods: 1. string_obj+="there"; this will modify the string_object. 2. string_obj.append("there!") 3. string_obj.insert(3," ") //it will insert the space after 3 characters of string_obj 4. string_obj.erase(3,Number of characters to remove) string_obj.erase(3) will remove every character after 3 characters of string obj string_obj.erase(string_obj.length()-1) will get rid of last character. or use string_obj.pop_back() will do it. 5. string_obj.replace(starting index,length,"string to be in place"); 6. string_obj.find("string to be found"); will return the starting index. we can sensor some string by this method: string_obj.replace(string_obj.find("word to be sensored"),string_obj.sizeof(),"******"); string line="hi"; line*=4; cout<<line<<endl; will throw error, we can't multiply string with integer. 7. string_obj.substr(starting index, no of characters) 8. string_obj.find_first_of("string/char to be found"); it will return npos i.e. unsigned x=-1 value; if character is absent in string. it is called npos which is set as -1. it is used for searching of characters: if(string_obj.find_first_of("!")==-1) cout<<"NOT FOUND"; if(string_obj=="whatever") cout<<"equal"; we can also use compare method to compare strings if(string_obj.compare("whatever")==0) cout<<"equals"; //returns zero if two strings are equal. //in java we have to use compare method */ }