print('--------------if语句--------------')

i = 5

if i <= 3:

print('1<=3 is true')

elif 4 <= i <= 5:

print('4<=i<=5 is false')

else:

print('others')

print('--------------while语句--------------')

it = 0

sum = 0

while it <= 10:

sum += it

it += 1

print(f'sum={sum}')

print('--------------for语句--------------')

for i in range(1, 10):

print(i, end=' ')

print()

print('--------------for语句--------------')

it = 1

while it < 3:

it += 1

else:

print(f'else: it={it}')

print('--------------跳转语句--------------')

for i in range(1, 5):

for j in range(1, i + 1):

if (i <= j):

continue

print(f'[{i},{j}]',end='')

print()