遇到“清理:"在Xcode中的Foundation代码示例中.这是什么?

问题描述

因此在即将发布的 Core Audio Book 我遇到了一个陌生的符号

so in some sample code from this upcoming Core Audio Book i've encountered an unfamiliar symbol

cleanup:

在调用某些dispose(myStuff)函数之前使用.它前面没有'@'或'#'.似乎您可以输入任何单词，后跟冒号，它会像注释一样起作用吗?

which is used before some dispose(myStuff) functions are called. It's not preceded by an '@' or a '#'. Seems you can type any word, followed by a colon, and it will act like a comment?

int main (int argc, const char * argv[])
{
    @autoreleasepool
    {
        NSLog(@"i am code.");

    cleanup:
    foop:
    lol:

        NSLog(@"even more code.");
    }
    return 0;
}

推荐答案

这不是评论.这是一个标签，指定goto的位置.

It's not a comment. It's a label specifying a location for goto.

例如

int main (int argc, const char * argv[])
{
    while (1) {
        printf("Is this an infinite loop?\n");
        goto endLabel;
    }

    endLabel:

    printf("No.");

    return 0;
}

输出:

Is this an infinite loop?
No.

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