C++ Functions: Complete Guide

1 year ago
Isabella Edwards
1 minute

In C++, the ways to use functions include defining functions, declaring functions, invoking functions, and passing arguments.

  1. Function definition: The general syntax for defining a function in C++ is:
返回类型 函数名(参数列表) {
    // 函数体
}

For example,

As an illustration,

int add(int a, int b) {
    return a + b;
}
  1. Declare a function: If a function is defined after the main function, it needs to be declared beforehand. The syntax for declaring a function is:
返回类型 函数名(参数列表);

For example:

int add(int a, int b);
  1. Call function: when calling a function, use the function name and a list of parameters. For example:
int result = add(3, 4);
  1. Passing parameters: You can pass parameters to a function by value, by reference, or by pointer. For example:

Pass by value:

void modify(int a) {
    a = a + 1;
}

int num = 5;
modify(num);
// num的值仍然是5

Quote transmission:

void modify(int &a) {
    a = a + 1;
}

int num = 5;
modify(num);
// num的值变为6

Pass by reference:

void modify(int *a) {
    *a = *a + 1;
}

int num = 5;
modify(&num);
// num的值变为6

By using these methods, you can correctly define, declare, and call functions in C++ while passing parameters.

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