1打印十行十列小星星(2个循环)j=0
while j<10:i=0while i<10:print("*",end="")i+=1print()j+=1

2打印十行十列小星星(隔行换色小星星,两个循环)
#外层循环动一次,内层循环动10次,外层循环动的慢,内层循环动的快
i=0
while i<10:j=0while j<10:if j%2==0:print("*",end="")else:print("#",end="")j+=1print()i+=1

3打印十行十列小星星(隔行换色小星星,两个循环)外层循环动一次,内层循环动10次,外层循环动的慢 ,内层循环动的快
i=0
while i<10:j=0while j<10:if i%2==0:print("*",end="")else:print("#",end="")j+=1print()i+=1