关于 c++ 中 std::cout 的效率以及打印消息的替代方法

发布于 2025-01-11 23:28:42 字数 977 浏览 4 评论 0原文

我正在学习 C++，作为练习，我正在实现一个粗略的 ASCII 渲染器，我的渲染函数看起来像这样：

void render() {
    for(int y = 0;y < height;y++) {
        for(int x = 0;x < width;x++) {
            std::cout << getCharOfPixel(x, y);
        }
        std::cout << '\n';
    }
}

但我想知道将整个内容存储在字符串中并打印出整个内容是否会更有效一次字符串，如下所示：

void render() {
    std::string finalString((width + 1) * height, '\0'); // initializing the string with ((width + 1) * height) null characters, to avoid resizing efficiency lack
    int characterIndex = 0; // where we are writing to finalString
    for(int y = 0;y < height;y++) {
        for(int x = 0;x < width;x++) {
            finalString[characterIndex++] = getCharOfPixel(x, y);
        }
        finalString[characterIndex++] = '\n';
    }
    std::cout << finalString;
}

更具体地说，我问 std::cout 的效率是否取决于我正在写入的字符数或调用它的次数

原文

I'm learning C++, and as a exercise i am implementing a crude ASCII renderer, and my render function looks something like this:

void render() {
    for(int y = 0;y < height;y++) {
        for(int x = 0;x < width;x++) {
            std::cout << getCharOfPixel(x, y);
        }
        std::cout << '\n';
    }
}

but i wonder if it could be more efficient to store the whole thing in a string and just print out the whole string at once, like this:

void render() {
    std::string finalString((width + 1) * height, '\0'); // initializing the string with ((width + 1) * height) null characters, to avoid resizing efficiency lack
    int characterIndex = 0; // where we are writing to finalString
    for(int y = 0;y < height;y++) {
        for(int x = 0;x < width;x++) {
            finalString[characterIndex++] = getCharOfPixel(x, y);
        }
        finalString[characterIndex++] = '\n';
    }
    std::cout << finalString;
}

more specifically, I'm asking if the efficiency of std::cout depends on how many characters i am writing or how many times i invoke it

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