小编Pie*_*son的帖子

查看简化的代码 - 我很困惑......

#include <stdio.h>
#include <string>      
#include <cstdlib>  // includes the standard library and overarchs over stdlib.h

using namespace std;  
void main()
{
    char buffer[10];
    string theString;
    int i = 997799; //(simplified)
    itoa(i,buffer,10);                      
    theString = buffer;             

    printf("\n string is: %s of length %d \n", theString, theString.length());
    printf("\n buffer is: %s of length %d \n", buffer, theString.length());
    return;
}

我得到的输出是出乎意料的：

string is: (null) of length 926366009
buffer is: 997799 of length 6

(1)为什么字符串打印为null？

(2) 为什么 theString.length() 在第一个 printf() 中打印不正确，但在第二个 printf() …

当我调用我的calculatePlaneEQ函数时,当我分配值时,它会抛出一个访问冲突...我的指针生锈了,但似乎这应该有效!

float *planeCoefA, *planeCoefB, *planeCoefC, *planeCoefD = NULL;

呼叫:

calculatePlaneEQ (<...>, &planeCoefA, &planeCoefB, &planeCoefC, &planeCoefD);

DEF:

void calculatePlaneEQ (<...>, float ** myXnorm, float ** myYnorm, float ** myZnorm, float** myD)
{
    float  xNorm = 1.3;
    float  yNorm = 1.4;
    float  zNorm = 1.5;
    float eqD = 1.6; 

    *(*myXnorm) = xNorm;
    *(*myYnorm) = yNorm;
    *(*myZnorm) = zNorm;
    *(*myD) = eqD;  
}