mirror of
https://github.com/adambard/learnxinyminutes-docs.git
synced 2024-12-23 09:41:36 +00:00
Edit wording on in c changes.
This commit is contained in:
parent
de5a359faa
commit
f28d33fb18
@ -39,7 +39,7 @@ Multi-line comments look like this. They work in C89 as well.
|
||||
|
||||
//print formatting:
|
||||
"%d" // integer
|
||||
"%3d" // minimum length of 3 digits for integer (right justifies text)
|
||||
"%3d" // integer with minimum of length 3 digits (right justifies text)
|
||||
"%s" // string
|
||||
"%f" // float
|
||||
"%ld" // long
|
||||
@ -51,7 +51,7 @@ Multi-line comments look like this. They work in C89 as well.
|
||||
"%o" // octal
|
||||
"%%" // prints %
|
||||
|
||||
// Constants: use #define keyword, no semicolon at end.
|
||||
// Constants: #define <keyword> (no semicolon at end)
|
||||
#define DAYS_IN_YEAR = 365
|
||||
|
||||
//enumeration constants are also ways to declare constants.
|
||||
@ -62,7 +62,6 @@ enum days {SUN = 1, MON, TUE, WED, THU, FRI, SAT};
|
||||
#include <stdlib.h>
|
||||
#include <stdio.h>
|
||||
#include <string.h>
|
||||
#include <ctype.h>
|
||||
|
||||
// (File names between <angle brackets> are headers from the C standard library.)
|
||||
// For your own headers, use double quotes instead of angle brackets:
|
||||
@ -111,7 +110,7 @@ int main() {
|
||||
unsigned int ux_int;
|
||||
unsigned long long ux_long_long;
|
||||
|
||||
// chars inside single quotes '*' are integers in your character set.
|
||||
// chars inside single quotes are integers in machine's character set.
|
||||
'0' //==> 48 on the ASCII character set.
|
||||
'A' //==> 65 on the ASCII character set.
|
||||
|
||||
@ -226,20 +225,14 @@ int main() {
|
||||
0 || 1; // => 1 (Logical or)
|
||||
0 || 0; // => 0
|
||||
|
||||
//Conditional expression ( ?: )
|
||||
//Conditional expression ( ? : )
|
||||
int a, b, z;
|
||||
z = (a > b) ? a : b; // z = max(a, b);
|
||||
z = (a > b) ? a : b; // "if a > b return a, else return b."
|
||||
|
||||
//Increment and decrement operators:
|
||||
int j = 0;
|
||||
char s[];
|
||||
int w = 0;
|
||||
j++; //difference between postfix and prefix explained below
|
||||
++j; // in string example.
|
||||
j--;
|
||||
--j;
|
||||
s[j++]; //returns value of j to s THEN increments value of j.
|
||||
s[++j]; //increments value of j THEN returns value of j to s.
|
||||
// same with j-- and --j
|
||||
|
||||
// Bitwise operators!
|
||||
~0x0F; // => 0xF0 (bitwise negation, "1's complement")
|
||||
@ -267,12 +260,6 @@ int main() {
|
||||
printf("I print\n");
|
||||
}
|
||||
|
||||
// Notes:
|
||||
// Loops MUST always have a body. If no body is needed, do this:
|
||||
for (i = 0; i <= 5; i++) {
|
||||
; // use semicolon to act as the body (null statement)
|
||||
}
|
||||
|
||||
// While loops exist
|
||||
int ii = 0;
|
||||
while (ii < 10) { //ANY value not zero is true.
|
||||
@ -297,6 +284,12 @@ int main() {
|
||||
|
||||
printf("\n");
|
||||
|
||||
// *****NOTES*****:
|
||||
// Loops MUST always have a body. If no body is needed, do:
|
||||
for (i = 0; i <= 5; i++) {
|
||||
; // use semicolon to act as the body (null statement)
|
||||
}
|
||||
|
||||
// branching with multiple choices: switch()
|
||||
switch (some_integral_expression) {
|
||||
case 0: // labels need to be integral *constant* epxressions
|
||||
@ -448,18 +441,20 @@ int add_two_ints(int x1, int x2)
|
||||
return x1 + x2; // Use return to return a value
|
||||
}
|
||||
|
||||
// Must declare a 'funtion prototype' before main() when creating functions
|
||||
// in file.
|
||||
// Must declare a 'funtion prototype' when creating functions before main()
|
||||
void getInt(char c); // function prototype
|
||||
int main() {
|
||||
int main() { // main function
|
||||
return 0;
|
||||
}
|
||||
void getInt(char w) { //parameter name does not need to match function prototype
|
||||
;
|
||||
}
|
||||
//if function takes no parameters, do: int getInt(void); for function prototype
|
||||
// and for the function declaration: int getInt(void) {}
|
||||
// this is to keep compatibility with older versions of C.
|
||||
|
||||
//if function takes no parameters, do:
|
||||
int getInt(void); for function prototype
|
||||
// and for the function declaration:
|
||||
int getInt(void) {}
|
||||
// (this is to keep compatibility with older versions of C).
|
||||
|
||||
/*
|
||||
Functions are call by value. So when a function is called, the arguments passed
|
||||
@ -485,11 +480,13 @@ void str_reverse(char *str_in)
|
||||
}
|
||||
}
|
||||
|
||||
/////////////////////////////////////
|
||||
// Built in functions:
|
||||
/////////////////////////////////////
|
||||
// from stdio.h:
|
||||
int c = getchar(); //reads character from input. If input = hi, only h is read.
|
||||
// getchar() can be stored into int or char. I am using int because
|
||||
// char is not large enough to store EOF used below.
|
||||
// getchar()
|
||||
int c = getchar(); //reads character from input.
|
||||
// If input = hi, 'h' is returned then next call, 'i' returned.
|
||||
while ((c = getchar()) != EOF) { // EOF constant "end of file".
|
||||
// Linux: CTRL+D, Windows: CTRL+X
|
||||
// must have () around getchar() as != is run before =.
|
||||
|
Loading…
Reference in New Issue
Block a user