Connect and share knowledge within a single location that is structured and easy to search. This article will explain several methods of getting the length of a char array in C. Array size can be calculated using sizeof operator regardless of the element data type. All it needs to do it, hold the address. On different machines it can be a different size. DelftStack articles are written by software geeks like you. On mine it's 4. In 64 bit System - 8 byte. Subhra Kanti Sahu, Actually a pointer is just a address holder so its size is always that of an int data type,what ever may be the type of pointer.In a 16-bit compiler,its 2 bytes and in 32-bit compiler,its 4 bytes(ie depeds on sizeof(int)). Addresses are always numbers and it cant be a character, a string or real/floating/double numbers. Pointer is a variable that points to a specific location of memory (i.e. sizeof an array, on the other hand, outputs the size of the array, in this case, 20*sizeof(char) = 20. It falls back to sorting by highest score if no posts are trending. But pointer variables of any data type will always have same number of bytes occupied in the memory. Why does Better Call Saul show future events in black and white? In c++, if the pointer object characterized like a type of char ,int or float in array. Then sizes of both arrays are retrieved using the sizeof operator and printed to the console.if(typeof ez_ad_units!='undefined'){ez_ad_units.push([[336,280],'delftstack_com-medrectangle-3','ezslot_4',113,'0','0'])};if(typeof __ez_fad_position!='undefined'){__ez_fad_position('div-gpt-ad-delftstack_com-medrectangle-3-0')}; Note that the second array size is equal to 18 bytes even though there are only 17 printed elements. That is why we get 4 for both ptri and ptrc. LOGIN to continue using GeekInterview website. A-143, 9th Floor, Sovereign Corporate Tower, We use cookies to ensure you have the best browsing experience on our website. sizeof s1 is thus stricly equivalent to sizeof (char[20]) and returns 20. sizeof s is stricly equivalent to sizeof (char*) and returns the size of a pointer to char (64 bits in your case). What is "Rosencrantz and Guildenstern" in _The Marvelous Mrs. Maisel_ season 3 episode 5? A pointer variable of type float holds only the address of floating point variable. Thus the sizeof operator includes this byte in the sum of all elements and returns the corresponding result.if(typeof ez_ad_units!='undefined'){ez_ad_units.push([[580,400],'delftstack_com-medrectangle-4','ezslot_2',112,'0','0'])};if(typeof __ez_fad_position!='undefined'){__ez_fad_position('div-gpt-ad-delftstack_com-medrectangle-4-0')}; In some scenarios, char arrays that were initialized or stored as the null-terminated character strings can be measured for size using the strlen function, which is part of the C standard library string utilities.if(typeof ez_ad_units!='undefined'){ez_ad_units.push([[580,400],'delftstack_com-box-4','ezslot_3',109,'0','0'])};if(typeof __ez_fad_position!='undefined'){__ez_fad_position('div-gpt-ad-delftstack_com-box-4-0')}; If we run the previous example code with strlen calculated values, we get different numbers caused by separate issues. 468), Monitoring data quality with Bigeye(Ep. But still the address of all these type of pointer variable is number. What does "dereferencing" a pointer mean? Come write articles for us and get featured, Learn and code with the best industry experts. The first - arr object size is printed to be 24 bytes because the strlen function iterates through a char array until the terminating null byte is encountered. Difference between passing pointer to pointer and address of pointer to any function, Difference between Dangling pointer and Void pointer, Data Structures & Algorithms- Self Paced Course, Complete Interview Preparation- Self Paced Course. sizeof(s1) is the size of the array in memory, in your case 20 chars each being 1 byte equals 20. sizeof(s) is the size of the pointer. Why does sdk expression need to be by the end of the bash_profile file? How to fit many graphs neatly into a paper? Bit fields memory aligment with unsigned int, short int. For Example, if the computer allocates 2 bytes for pointer variable, then all the pointer variables, irrespective of their data type, will occupy 2 bytes in the memory.. If you observe the output of above C program you can see that pointer variables, irrespective of their data type, consume 4 bytes of data in the memory. Note: Observe that Im using %d as format specifier while printing the size of data type, thats because sizeof() function/method returns integer type data i.e., number of bytes occupied in the computers memory.if(typeof ez_ad_units != 'undefined'){ez_ad_units.push([[300,250],'technotip_com-box-4','ezslot_1',139,'0','0'])};if(typeof __ez_fad_position != 'undefined'){__ez_fad_position('div-gpt-ad-technotip_com-box-4-0')}; Note: sizeof() method takes a single argument and it is not a function whose value is determined at run time, but rather an operator whose value is determined by compiler so its called as compile time unary operator.if(typeof ez_ad_units != 'undefined'){ez_ad_units.push([[250,250],'technotip_com-banner-1','ezslot_8',113,'0','0'])};if(typeof __ez_fad_position != 'undefined'){__ez_fad_position('div-gpt-ad-technotip_com-banner-1-0')}; For list of all c programming interviews / viva question and answers visit: C Programming Interview / Viva Q&A List, For full C programming language free video tutorial list visit:C Programming: Beginner To Advance To Expert, Your email address will not be published. Yes. All pointer types take same number of bytes for a compiler. Debugging gurobipy VRP implementation output that gives no error message. On 64 bit machine it has 8 bytes. How can I get the list of files in a directory using C or C++? If you also would like to contribute to DelftStack by writing paid articles, you can check the, Difference Between Unsigned Int and Signed Int in C. What is the nature of a demiplane's walls? Writing code in comment? The operand of sizeof can either be the parenthesized name of a type or an expression but in any case, the size is determined from the type of the operand only. Thus, calling strlen on arr object resulted in iterating over both arr and arr2, since the first array is not terminated with null byte and the compiler stored the arr2 continuously after it, resulting in a size equal to the sum of both arrays minus 1 (discarding the terminating null byte). Also note that addresses are unique. (4 bytes for pointer data type). The sizeof operator returns the size of a type. How can I refill the toilet after the water has evaporated from disuse? REST Endpoint using MIT and BSD 3-clause license libraries. Note: But the number of bytes allocated for different data types and pointer variables are machine dependent. Trying to relate microphone sensitivity and SPL. Announcing the Stacks Editor Beta release! External hard drive not working after unplugging while Windows Explorer wasn't responding. acknowledge that you have read and understood our, GATE CS Original Papers and Official Keys, ISRO CS Original Papers and Official Keys, ISRO CS Syllabus for Scientist/Engineer Exam, Pointers in C and C++ | Set 1 (Introduction, Arithmetic and Array), Types of Models in Object Oriented Modeling and Design, Dynamic Memory Allocation in C using malloc(), calloc(), free() and realloc(). Why isn't sizeof for a struct equal to the sum of sizeof of each member? Why the size of pointer variable is 2 bytes ? Although, when measuring the arrays size, there might be some hideous errors if the inner details are ignored. If you think the above answer is not correct, Please select a reason and add your answer below. Why would an F-35 take off with air brakes behind the cockpit extended? Find centralized, trusted content and collaborate around the technologies you use most. Why classical mechanics is not able to explain the net magnetization in ferromagnets? Get access to ad-free content, doubt assistance and more! If the compiler support 32-bit, then size of char * is 4 BYTES. Please use ide.geeksforgeeks.org, More like San Francis-go (Ep. One more thing, you should use %zu for size_t type in printf format. The cause of this issue is hiding in the method of initialization, namely when char array is initialized using a string literal value, the terminating null byte is also stored as a part of the array. Years of experience when hiring a car - would a motorbike license count? A char pointer variable holds only the address of char type variable. It is only possible when we declare char pointer (char *p) and print the ("%d",sizeof(p)) while not giving 4 bytes on ("%d",sizeof(*p)) why? Get invaluable Interview and Career Tips delivered directly to your inbox. Announcing Design Accessibility Updates on SO. I'm wondering how does the 8 come from, thanks! In other words, sizeof() works the same way for pointers as for standard variables. So the pointer address contains the 2 bytes address. Combining C++ and C - how does #ifdef __cplusplus work? Copyright 2014-2022 GeekInterview.com | All Rights Reserved. You just need to take into account the target platform when using pointers. Namely, the following example is initializing two arrays named arr and arr2 with different notations. Improve INSERT-per-second performance of SQLite. Please contact me if you there is any issue with the download. Is it really necessary considering the "wrong" position and normal behavior? By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. Write a program that calculates and prints the bill . C Program To Find Area and Circumference of Circle using Pointer, Pointer To A Pointer In C Programming Language, Sizeof Operator in C Programming Language, Basics of Pointers In C Programming Language, https://www.youtube.com/watch?v=_EaAZYSvBog, C Programming: Beginner To Advance To Expert, C Program To Add Two Numbers using Pointers, C Program to Print Integer Numbers Till N, Prime Numbers using Sieve of Eratosthenes: C Program, Find Prime Numbers from 2 To N using Sieve of Eratosthenes: C Program, Verify The Transaction on Mainnet: XUMM SDK, Send Sign Request As Push Notification: XUMM SDK, Send Ping Request To XUMM Platform and Get Application Details. Required fields are marked *. How do I change the sans serif font in my document? RAM). Just had a doubt what if we are to find sizeof(*s) ? Lets write a C program to find out the size or the number of bytes occupied by pointer variables of different data type in your computers memory.if(typeof ez_ad_units != 'undefined'){ez_ad_units.push([[300,250],'technotip_com-medrectangle-3','ezslot_2',110,'0','0'])};if(typeof __ez_fad_position != 'undefined'){__ez_fad_position('div-gpt-ad-technotip_com-medrectangle-3-0')}; Related Read:Sizeof Operator in C Programming LanguageBasics of Pointers In C Programming Language, Video Tutorial: C Program To Find Size of Pointer Variables. Note that, lengthOfArray function implemented by us imitates the strlen counting behavior and results in the same numbers. Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide. 8 is the size of a pointer, an address. Your email address will not be published. that is correct in a 32-bit system. Get your news alert set up today, Once you confirm your Email subscription, you will be able to download Job Inteview Questions Ebook . KNN: Should we randomly pick "folds" in RandomizedSearchCV? Output:Size of int pointer = 4 bytes.Size of char pointer = 4 bytes.Size of float pointer = 4 bytes.Size of double pointer = 4 bytes.Size of long int pointer = 4 bytes.Size of short int pointer = 4 bytes. reverse translation from amino acid string to DNA strings, Animated show where a slave boy tries to escape and is then told to find a robot fugitive. If you want the length of the C-string pointed by s, you could use strlen(s). How Can Cooked Meat Still Have Protein Value? it is giving me 1 byte but it should have been 3 bytes for "fyc". Notify me of follow-up comments by email. There cant be 2 location in your computers memory with same address. Consider a compiler where int takes 4 bytes, char takes 1 byte and pointer takes 4 bytes. Size of a pointer is fixed for a compiler. Concatenate two circularly single linked list into one circularly linked list, Test scenarios for 'create and send email' functionality. 16-bit, 32-bit, 64-bit computers allocate different bytes of memory. Trending sort is based off of the default sorting method by highest score but it boosts votes that have happened recently, helping to surface more up-to-date answers. (A) sizeof arri[] = 3sizeof ptri = 4sizeof arrc[] = 3sizeof ptrc = 4(B) sizeof arri[] = 12sizeof ptri = 4sizeof arrc[] = 3sizeof ptrc = 1(C) sizeof arri[] = 3sizeof ptri = 4sizeof arrc[] = 3sizeof ptrc = 1(D) sizeof arri[] = 12sizeof ptri = 4sizeof arrc[] = 3sizeof ptrc = 4Answer: (D)Explanation: Size of an array is number of elements multiplied by the type of element, that is why we get sizeof arri as 12 and sizeof arrc as 3. How does sizeof() work for char* (Pointer variables)? It doesn't matter which type of variable it is pointing to. To test different type sizes on your machine you can just pass the type instead of a variable like so printf("%zu %zu\n", sizeof(char*), sizeof(char[20]));. Why is sizeof(str) is equal to 8 , when it should be equal to strlen(str)+1 (because of extra null char)? Chi squared test with reasonable sample size results in R warning, Derivation of the Indo-European lemma *brhtr brother. rev2022.8.2.42721. sizeof(char *) is the size of the pointer, so normally 4 for 32-bit machine, and 8 for 64-bit machine. 469). [duplicate], size of character array and size of character pointer, San Francisco? Why does the string I copied using strncpy have junk instead of the last character? Kindly clarify this doubt. It will print 4 and 20 respectively on a 32bit machine. For the second array object - arr2, strlen returned the number of printed characters without the last null byte, which can be useful in some scenarios, but it does not represent the arrays actual size. generate link and share the link here. Site design / logo 2022 Stack Exchange Inc; user contributions licensed under CC BY-SA. In 32 bit system - 4 byte Basically when ever we are using pointer that refers some other variables, when the pointers refer some variable means it contains it address and addresses are stored in integer format. If you are on a 64 bit computer, the memory addresses are 64 bit, therefore a 64 bit (8 bytes x 8 bits per byte) numeric value must be used to represent the numeric pointer variable (char*). Same is true for char pointers also, therefore size of char pointer is 4 bytes. How do I use extern to share variables between source files? By using our site, you
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