小编Kha*_*mes的帖子

在最近的家庭作业中,我被告知使用long变量来存储结果,因为它可能是一个很大的数字.

我决定检查它对我来说真的很重要,在我的系统上(intel core i5/64-bit windows 7/gnu gcc编译器)并发现以下代码:

printf("sizeof(char) => %d\n", sizeof(char));
printf("sizeof(short) => %d\n", sizeof(short));
printf("sizeof(short int) => %d\n", sizeof(short int));
printf("sizeof(int) => %d\n", sizeof(int));
printf("sizeof(long) => %d\n", sizeof(long));
printf("sizeof(long int) => %d\n", sizeof(long int));
printf("sizeof(long long) => %d\n", sizeof(long long));
printf("sizeof(long long int) => %d\n", sizeof(long long int));

产生以下输出:

sizeof(char) => 1
sizeof(short) => 2
sizeof(short int) => 2
sizeof(int) => 4
sizeof(long) => 4
sizeof(long int) => 4
sizeof(long long) => 8
sizeof(long long int) => …

在格式化发送到R中的函数的文本字符串时,我遇到使用双引号的问题.

考虑一个示例功能代码:

foo <- function( numarg = 5, textarg = "** Default text **" ){ 
    print (textarg)
    val <- numarg^2 + numarg
    return(val) 
}

使用以下输入运行时:

foo( 4, "Learning R is fun!" )

输出是:

[1] "Learning R is fun!"
[1] 20

但是,当我尝试(以各种方式,如此处所示)写"R"而不是R时,我得到以下输出:

> foo( 4, "Learning R is fun!" )
[1] "Learning R is fun!"
[1] 20
> foo( 4, "Learning "R" is fun!" )
Error: unexpected symbol in "funfun( 4, "Learning "R"
> foo( 4, "Learning \"R\" is …