- C Programming Examples
- C Programming Examples
- C Print Hello World
- C Get Input from User
- C Print Integer
- C Add Two Numbers
- C Add Subtract Multiply Divide
- C Add n Numbers
- C Area Perimeter of Square
- C Area Perimeter of Rectangle
- C Area Circum of Circle
- C Fahrenheit to Celsius
- C Celsius to Fahrenheit
- C Inches to Centimeters
- C Kilogram to Gram
- C Reverse a Number
- C Swap Two Numbers
- C Interchange Numbers
- C Print ASCII Value
- C Print Fibonacci Series
- C Check Palindrome or Not
- C Check Armstrong or Not
- C Find Armstrong Numbers
- C Find nCr and nPr
- C Find Profit Loss
- C Sum of their Square
- C First & Last Digit Sum
- C Sum of All Digit
- C Product of All Digit
- C Print Total Digit in Number
- C Check Perfect Number
- C Find Basic Gross Salary
- C Round Number to Integer
- C Print Series upto n Term
- C Find Factors of Number
- C if-else & Loop Programs
- C Check Even or Odd
- C Check Prime or Not
- C Check Alphabet or Not
- C Check Vowel or Not
- C Check Leap Year or Not
- C Is Reverse Equal Original
- C Make Calculator
- C Add Digits of Number
- Count Positive Negative Zero
- C Largest of Two Numbers
- C Largest of Three Numbers
- C Smallest of Two Numbers
- C Smallest of Three Numbers
- C Find Factorial of Number
- C Find LCM & HCF
- C Find LCM of n Numbers
- C Find HCF of n Numbers
- C Find Arithmetic Mean
- C Find Average, Percentage
- C Find Student Grade
- C Print Table of Number
- C Print Prime Numbers
- C Find Discount Purchase
- C Calculate Parcel Charge
- C Calculate Wage of Labor
- C Print Phone Bill
- C Conversion programs
- C Decimal to Binary
- C Decimal to Octal
- C Decimal to Hexadecimal
- C Binary to Decimal
- C Binary to Octal
- C Binary to Hexadecimal
- C Octal to Decimal
- C Octal to Binary
- C Octal to Hexadecimal
- C Hexadecimal to Decimal
- C Hexadecimal to Binary
- C Hexadecimal to Octal
- C Pattern Programs
- C Pattern Printing Programs
- C Print Diamond Pattern
- C Print Floyd's Triangle
- C Print Pascal's Triangle
- C Array Programs
- C 1D Array Programs
- C Linear Search
- C Binary Search
- C Largest Element in Array
- C Smallest Element in Array
- C Second Largest/Smallest
- C Count Even Odd
- C Array Element at Even
- C Array Element at Odd
- C Print Even Array Elements
- C Print Odd Array Elements
- C Sum/Product of Even/Odd
- C Reverse an Array
- C Insert Element in Array
- C Delete Element from Array
- C Merge Two Arrays
- C Bubble Sort
- C Selection Sort
- C Insertion Sort
- C Print Common Elements
- C 2D Array Programs
- C Add Two Matrices
- C Subtract Two Matrices
- C Transpose a Matrix
- C Multiply Two Matrices
- C Sum All Matrix Elements
- C Largest Element in Matrix
- C Print Row Column Total
- C 3D Array Programs
- C String Programs
- C Print String
- C Find Length of String
- C Compare Two String
- C Copy a String
- C Concatenate String
- C Reverse a String
- C Count Vowels Consonants
- C Replace Vowel in String
- C Delete Vowels from String
- C Delete Word from String
- C Frequency of Character
- C Count Word in String
- C Remove Spaces from String
- C Sort a String
- C Sort String in Alphabetical
- C Sort Words in Ascending
- C Sort Words in Descending
- C Uppercase to Lowercase
- C Lowercase to Uppercase
- C Swap Two Strings
- C Check Anagram or Not
- C Check Palindrome String
- C Print Number in Words
- C Print Successive Character
- C Character without Space
- C File Programs
- C Read a File
- C Write Content to File
- C Read & Display File
- C Copy a File
- C Merge Two Files
- C Reverse File
- C Count All Character in File
- C List Files in Directory
- C Encrypt & Decrypt a File
- C Delete a File
- C Misc Programs
- Generate Random Numbers
- C Print Date Time
- C Print Message with Time
- C Get IP Address
- C Print Smiling face
- C Pass Array to Function
- Add Two Numbers using Pointer
- C Address of Variable
- C Shutdown Computer
- C Programming Tutorial
- C Tutorial
C program to find the length of a string
In this article, you will learn and get code about how to find and print the length of any given string given by the user (at run-time) using the following approaches:
- Find the length of a string using the strlen() function
- Find the length of a string without using the strlen() Function
- Find the length of a string using a user-defined Function
Print the length of a string using the strlen() function
To find the length of any given string in C programming, you have to ask the user to enter the string and then find its length using the strlen() function of the string.h library, as shown in the program given below:
#include<stdio.h> #include<conio.h> #include<string.h> int main() { char str[20]; int len; printf("Enter the string: "); gets(str); len = strlen(str); printf("\nLength of the string = %d", len); getch(); return 0; }
As the above program was written in the Code::Blocks IDE, here is the first snapshot of the sample run:
Now supply any string, say "codescracker," and press the ENTER key to see the length of the given string as shown here in the second snapshot:
The function named strlen() takes one argument as a string and returns the length. Therefore, the length of the string, say str, gets returned by the function strlen() and initialized to the variable len. Print the value of len as output.
Find the length of a string without using the strlen() function
This program does not use the strlen() function to find the length; rather, the length gets calculated manually here:
#include<stdio.h> #include<conio.h> int main() { char ch[20]; int count=0, i; printf("Enter any string: "); scanf("%s", ch); for(i=0; ch[i]!='\0'; i++) count++; printf("\nLength of the String = %d", count); getch(); return 0; }
Here is its sample run:
Enter any string as input, for example, codescracker, and press the ENTER key to see its length as output:
As in the above program, the string was received from the user using the scanf() function. As a result, whenever the user enters a string that contains spaces, only the first word is received and the rest is skipped. Here is a sample run in which the user entered any string containing space, such as "codes cracker,"
As you can see, the word before the space is "codes," therefore the program will only calculate the length of "codes" that will be 5. To solve this problem, we have to use the gets() function in place of scanf() to receive the string (along with spaces) from the user, as shown in the program given below:
#include<stdio.h> #include<conio.h> int main() { char str[100]; int count=0, i; printf("Enter any string: "); gets(str); for(i=0; str[i]!='\0'; i++) count++; printf("\nLength of the String = %d", count); getch(); return 0; }
Here is the final snapshot of the first sample run:
Now let's take another sample run where the user enters a string that contains spaces, say "codes cracker." Here is the final snapshot of the second sample run:
Program Explained
- Receive any string as input using the gets() function.
- Use a for loop to start from the first character of the string to the last.
- If the null-terminated character ('\0') appears, it indicates that nothing is left in the string.
- Therefore, until the null-terminated character comes, increase the value of the count variable each and every time the program flow goes inside the for loop.
- The count variable is initialized to 0 at the beginning of the program.
- Therefore, from the first character to the last character of the string, the count variable will be incremented each and every time.
- It means that the count variable at last will hold the length of the string; that is, how many characters are present inside the string, say str.
- Finally, print the value of count that shows the length of the string.
Find string length using a user-defined function
This program is made using user-defined functions to do the same job as the previous one:
#include<stdio.h> #include<conio.h> int findStringLen(char str[50]); int main() { char str[50]; int len; printf("Enter any string: "); gets(str); len = findStringLen(str); printf("\nLength of the String = %d", len); getch(); return 0; } int findStringLen(char s[50]) { int i, count=0; for(i=0; s[i]!='\0'; i++) count++; return count; }
Here is the final snapshot of the sample run:
The same program in different languages
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