# Some Stuff on Programming
## Variables (變數)
- Stores data associated with the defined variable name
- EX:
```c=
// 定義一個名為 "luckyNumber" 的變數(整數)
int luckyNumber;
// 設 luckyNumber 存的值為 5
luckyNumber = 5;
// 顯示 luckyNumber 加一後的值,為整數 6
printf("%d", luckyNumber+1);
```
- Example usage: display user input
```c=
int luckyNumber;
// 把使用者的輸入的值存到名為 luckyNumber 的變數裡面
scanf("%d", &luckyNumber);
// 顯示「你剛剛輸入的值是:%d」,在「%d」的部分顯示使用者剛剛輸入的值
printf("你剛剛輸入的值是:%d", luckyNumber);
```
## Conditional statement
- Kind of similar to 構成要件
- Concept is as follows:
```c=
if (statement) {
// Do something here
}
```
- Example:
```c=
int count = 3;
// 如果變數 count 的值是等於(==)整數 3,執行括號內的程序
if (count == 3) {
// 把 count 加一並存回於 count 裡
count = count + 1;
}
// count is now 4
```
## = 跟 == 的差別
- `=` 是設定值的(it's an assignment)
- `==` 是比較用的(equal to?)
```c=
// Assign the value of 2 to variable x
int x = 2;
// Checks if x is equal to 0
if (x == 0) {
printf("x is equals to zero!");
}
```