Fixed a compilation error and some spelling mistakes (#30984)

This commit is contained in:
Tzupy
2019-01-15 23:03:52 +02:00
committed by Tom
parent afa94e6dbc
commit db82a53408

View File

@ -1,15 +1,13 @@
---
title: Short-Circuit Evaluation
---
# Short-Circuit Evaluation
The Short-Circuit evaluation consists in checking or executing the second argument only if the first argument is not enough to determine the value of the expression.
The Short-Circuit evaluation consist in check or execute the second argument only if the first argument is not enough to determine the value of the expression.
You can do a short-circuit evaluation with && and || operators.
## Example with && operator:
You can do a short-circuit evaluation with `&&` and `||` operators.
### Example with `&&` Operator
```c
canOpenFile(filename) && openFile(filename); // If you can open the file then open it.
```
@ -22,7 +20,7 @@ The example above is equivalent to:
}
```
## Example with || operator:
### Example with `||` Operator
```c
isServerOn || startServer(); // If the server is not on then start it.
@ -35,7 +33,33 @@ The example above is equivalent to:
}
```
## Example with nested if statements
### A Real-World Example with `||` Operator
```c
#include <stdio.h>
#include <stdlib.h>
char *getName();
int main(int argc, char *argv[]) {
// Get the first argument passed via terminal
char *name = argv[1];
// If the name is not passed via terminal, then print a message and then get the name
name || printf("Please give me your name:") && (name = getName());
printf("Hello %s\n", name);
}
char *getName() {
// Allocate memory
char *name = (char*)malloc(30);
scanf("%s", name);
return name;
}
```
### Example with Nested `if` Statements
```c
int i, j;
@ -57,31 +81,6 @@ The example above is equivalent to:
```
Notice when `if ( i > 10 )` fails, the statement is false and the check `if ( j > 10 )` is never run. `if ( i > 10 && j > 10 )` behaves exactly the same way, because if `i > 10` is false then the entire statement is automatically false, and there is no need to run an additional check.
## Keep it all together in real example
```c
#include <stdio.h>
#include <stdlib.h>
char *getName();
int main(int argc, char *argv[]) {
// Get first argument passed via terminal
char *name = argv[1];
// If name is not passed via terminal then print message and then get the name
name || printf("Please give me your name:") && (name = getName());
printf("Hello %s\n", name);
}
char *getName() {
// Allocate memory
char *name = malloc(30);
scanf("%s", name);
return name;
}
```