问题描述
我有一个向量，想将整数转换为字符，然后将转换的字符推回向量。 我得到的是向量中的“不可见”元素，这不会导致明显错误，增加 vec.size() 计数，但在控制台输出期间不显示。我如何解决这个问题，使它们在向量中显示为正常/“可见”字符？请参阅下面的代码以演示错误。
#include <iostream>
#include <vector>
int main(int argc,const char * argv[]) {
std::vector<char> test{'a','b'};
int i = 5;
char h = char(i);
test.push_back(h);
for(auto i: test){
std::cout << "should be an element ->" << i << '\n';
}
std::cout<< "size of vec is -> " << test.size();
return 0;
}
解决方法
好吧，如果我们检查您正在打印的内容
import pygame,sys,math
screen = pygame.display.set_mode((640,480))
ground = []
class Player:
def __init__(self,x,y):
self.rect = pygame.Rect(x,y,32,32)
self.xv = 0
self.yv = 0
self.movement = [0,0]
self.actualYspd = 0
self.standingplatform = None
self.collision = {"top":False,"bottom":False}
def collision_check(self):
self.collision = {"top":False,"bottom":False}
#-------X collision
if self.standingplatform != None:
self.movement[0] += self.standingplatform.vec[0]#If the platform moves horizontally,it moves with the same x speed.
self.rect.x += math.ceil(self.movement[0])
hit_list = []
for i in ground:
if self.rect.colliderect(i):
hit_list.append(i)
for i in hit_list:
for j in range(abs(math.ceil(self.movement[0]))):
if self.rect.colliderect(i.rect):
self.rect.x += abs(self.movement[0])/self.movement[0] * -1
#-------Y collision
self.actualYspd = 0 #This variable holds the speed of the platform that the player is on.
if self.standingplatform != None:
self.rect.y += self.standingplatform.vec[1]
self.actualYspd = self.standingplatform.vec[1]
self.rect.y += math.ceil(self.movement[1])
hit_list = []
for i in ground:
if self.rect.colliderect(i.rect):
hit_list.append(i)
self.standingplatform = None
for i in platforms:
if self.rect.colliderect(i.rect):
self.standingplatform = i#Detects the moving platform to move along with it when player is on it.
for i in hit_list:
if self.movement[1] > 0:
self.collision["bottom"] = True
if self.movement[1] < 0:
self.collision["top"] = True
if i == self.standingplatform:#This is needed to stick the player to the platform
pushY = self.movement[1]
else:
pushY = self.movement[1] + self.actualYspd
for j in range(abs(math.ceil(pushY))):
if self.rect.colliderect(i.rect):
self.rect.y += abs(pushY)/pushY * -1
self.yv = 0
def loop(self):
self.movement = [0,0]
self.yv += 0.5
key = pygame.key.get_pressed()
if key[pygame.K_RIGHT]:
self.xv = 5
elif key[pygame.K_LEFT]:
self.xv = -5
if abs(self.xv) < 1:
self.xv = 0
self.xv *= 0.7
if self.yv > 15:
self.yv = 15
self.movement[0] += self.xv
self.movement[1] += self.yv
self.collision_check()
if self.collision["top"]:
self.yv = 0
if self.collision["bottom"]:
if key[pygame.K_UP]:
self.yv = -15
player = Player(0,0)
platforms = []
class moving_platform:
def __init__(self,w,h,vec):
self.vec = vec #2D vector that stores the velocity of the platform
self.rect = pygame.Rect(x,h)
ground.append(self)
platforms.append(self)
def loop(self):
self.rect.x += self.vec[0]
self.rect.y += self.vec[1]
#Platforms bounce off the screen
if self.rect.right > 640 or self.rect.left < 0:
self.vec[0] *= -1
if self.rect.bottom > 480 or self.rect.top < 0:
self.vec[1] *= -1
class platform:
def __init__(self,h):
self.rect = pygame.Rect(x,h)
ground.append(self)
platform(0,180,100,30)
moving_platform(0,1000,30,[0,3])
CLOCK = pygame.time.Clock()
FPS = 60
while True:
screen.fill((0,0))
for event in pygame.event.get():
if event.type == pygame.QUIT:
pygame.quit()
sys.exit()
for i in platforms:
i.loop()
for i in ground:
pygame.draw.rect(screen,(255,0),i.rect)
player.loop()
pygame.draw.rect(screen,(0,255),player.rect)
pygame.display.update()
CLOCK.tick(FPS)
以及数组中那些元素的值
should be an element ->a
should be an element ->b
should be an element ->♣
size of vec is -> 3
您正在为您的程序获得正确的输出。 如果您想将 5 转换为字符，则应在其中添加 '0' 字符。 所以像
vec[0] = 'a' (thats 97 integer value)
vec[1] = 'b' (thats 98 integer value)
vec[2] = '\x5' (thats 5 integer value)
将在字符中存储 65 或 '5' 的整数值。
注意：C/C++ 中的字符只是 8 位数字，当您打印它们时，您会从 ascii 表中获得以下字符之一。 ascii 表中的某些字符是不可打印的字符，例如值为 0 的字符为 NULL。 TAB 的值为 8（也可打印为 '\t'）或 ESC 为 27。
感谢所有的建议和意见。为了在此处提供清晰的信息，这是我试图实现的目标。
#include <iostream>
#include <vector>
int main(int argc,const char * argv[]) {
std::vector<char> test{'a','b'};
int i = 12345 ;
std::string w = std::to_string(i);
for(auto i : w){
test.push_back(i);
}
for(auto i : test){
std::cout << "element in the vector -> " <<i << '\n';
}
}