How to handle uninitialized variables in C language

When a variable in the C language is not initialized, its value is undefined and may contain any garbage value. To avoid undefined behavior and incorrect calculation results, several handling methods can be adopted.

1. Explicit initialization: when declaring a variable, assign it an explicit value such as 0, NULL, or another appropriate initial value.

int num = 0;
char str[10] = "";

1. Use assignment statements: immediately assign a value to a variable after declaring it to ensure that the variable has a reasonable initial value.

int num;
num = 0;

1. Allocate memory for pointer variables: If a variable is of pointer type, it needs to be allocated memory space before any assignment operation can be performed.

int* ptr;
ptr = (int*)malloc(sizeof(int));
*ptr = 0;

1. Default values can be used to initialize certain types of variables, such as an empty string being the default value for character arrays.

char str[10] = {0};

1. Be mindful of scope: variables declared in a local scope are initialized with garbage values by default, so it is necessary to initialize them before use.

void func() {
    int num;  // 未初始化的局部变量
    num = 0;  // 初始化变量
    // 其他代码
}

In conclusion, make sure to properly initialize C language variables before using them to avoid undefined behavior and incorrect results.