Stings Functions in C++
Hello people, today we are going to read about the
pre-defined functions of String datatype. If you work on C++ then you must have, atleast once, gone through the
confusion regarding the strings functions which are there in C++. String is the
most important data structure provided by the C++ language. To work more efficiently
on this data structure you must have the basic knowledge of the following functions
which are predefined in C++ or in <string> library :
1. 1. String.length(); or strlen();
2.
String.append();
3.
String.erase();
4.
Str.replace();
5.
Strcat();
6.
Strcmp();
7.
Strcpy();
8.
Reverse();
Let’s discuss each of these further in detail :
string.append();
Many people know about the basic functionality of this
function of string, i.e. APPEND but what people don’t about it is that we can use
this function with no. of variations in inputs. As the name suggests append
works like adding the two strings, i.e. STRING1 = STRING1 + STRING2
So the basic way in which we use this function to add two
string is as follows:
STRING1.append(STRING2)
But other ways in which we can change the functionality of
this append function is as follows:
STRING1 : “Coding”
STRING : "Winds"
STRING1.append(STRING2); //
"CodingWinds"
STRING1.append(STRING2,0,3); // "CodingWin"
STRING1.append("Winds",3); // "CodingWin"
STRING1.append("Platform"); //
"CodingPlatform"
STRING1.append(5u,'.'); //
"Coding....."
string.length();
or strlen();
These two functions are used to calculate the length of
strings. When using these we don’t need to write the whole function for calculating
length of the string. We can just define an integer variable and evaluate it with
these functions because these functions
return integers which is equal to the length of the string.
SYNTAX:
int
l = StringName.length();
OR
int l = strlen(StringName);
str.cmp(STRING1,STRING2)
This function of string helps in the comparision of strings
it returns 0 if STRING1 = STRING2, some negative value if STRING1 < STRING2
and some positive value if STRING1>STRING2.
str.erase();
This function is used to delete a part of string, for doing
the we can use this pre-defined function “string.erase();”
in the following ways :
str = “Coding Winds”
str.erase(); // This erases the whole string
str.erase(1,5); // ”C Winds”
str.erase(str.begin()+7); //”Winds”
str.erase(str.begin()+0,str.end()-6); //”Winds”
str.replace();
This function is responsible for replacing a part of string with other string or replacing a part of string with a part of other string. We can do this by using following methods :
str = “Coding”
str2 = “g Winds”
str3 = “g Best Platform”
str.replace(5,1,str2); // "Coding Winds" str.replace(5,1,str3,0,6);// "Coding Best"
str.replace(6,1,"just a ");// "Coding just a Best"
strcpy(str1,str2);
This copies str2 into the place of str1, i.e., this replaces
the str1 completely with str2. We can use this functions as follows :
str1 : “Code for good!”
str2 : “Coding Winds”
strcpy(str1,str2);
str1 : “Coding Winds”
str2 : “Coding Winds”
strcat(str1,str2);
This strcat() function concatenates str2 onto the ending of str1.
We can use this function in the following way :
str1 = “Coding”
str2 = “Winds”
strcat(str1,str2);
str1 = “CodingWinds”
str.erase();
This erase function of string datatypes helps us in deleting
a part of string. We can do this by following this code given below :
str = “Coding Winds”
str.erase(); // This erases the
whole string
str.erase(1,5); // ”C Winds”
str.erase(str.begin()+7); //”Winds”
str.erase(str.begin()+0,str.end()-6); //”Winds”
reverse();
Reverse is an inbuilt function, which helps in reversing a
string. And we can do this as follows :
String1 : “Coding Winds”
Syntax : reverse(str.begin(),str.end());
This implies reverse(String1.begin() , String1.end()) will
give an output string as :
“sdniW
gnidoC”
So yes, these are all basic functions of string in C++ which
you must know to use string datatype more efficiently. Hope you gain some
knowledge from this article. If you are aware of some other such string related
pre-defined functions then do let us know in the comment section.
And don’t forget to have us on your instagram (@coding.winds)
and also follow us on Linkedin (Coding Winds).
Thank You for giving this a read.
Keep Coding!
