1.什么是if判断
判断一个条件如果成立则做...不成立则做...
2.为何要有if判断
让计算机能够像人一样具有判断的能力
3.如何用if判断
‘‘‘
#语法1:
‘‘‘
if 条件1:
code1
code2
code3
.......
‘‘‘
age=18
if age != 18:
print(‘你好啊小伙子‘)
print(‘加个微信吧...‘)
print(‘other code...‘)
# 语法2:
if 条件:
code1
code2
code3
......
else:
code1
code2
code3
......
#
age=22
sex = ‘male‘
x=‘dd‘
is cool = True
if age>16 and age<25 and\
x=‘dd‘ and is cool:
print(‘你好‘)
else:
print(‘再见‘)
#
# 语法3
if 条件1:
if 条件2:
code1
code2
code3
code2
code3
.......
age = 18
sex = ‘hemale‘
shencai = ‘good‘
is_beautiful = True
is_rich = True
if age >16 and age< 25 and sex = ‘hemale‘\
and shencai = ‘good‘ and is_beautiful:
print (‘表白‘)
if is_rich:
print(‘在一起‘)
else:
print(‘你是谁‘)
else:
print(‘8888888‘)
# 语法4
if 条件1:
子代码块1
elif 条件2:
子代码块2
elif 条件3:
子代码块3
elif 条件4:
子代码块4
.............
else:
子代码块5
#
score = input(‘your score:‘)
score = int(score)
if score >= 90:
print(‘A‘)
elif score >= 80:
print(‘B‘)
elif score >= 70:
print(‘C‘)
else:
print(‘laji‘)
原文地址:https://www.cnblogs.com/xiamenghan/p/9648874.html