Conditional statements, branch statements, and logical and comparison operators in Python

if and Else statements in Python perform simple tests such as:

A = 3;b = 5;if a<b:print (' A small b large ') Else:print (' A big B small ')

Answer output:

A small B large

My understanding of conditional judgment if:

The so-called conditional judgment is actually if a<b we do the corresponding treatment otherwise (a greater than B case) we have to a>b the corresponding processing we have to judge a variable or an expression is only true when the corresponding processing when else is optional

Like what:

Name = ' Zhang San ' ismarry = ' true ' #表示某个人是否结婚时 #接下来只对真作出相应的处理 if Ismarry:print (name+ ' married ')

Answer output :

Zhang San married

You can also use the IF condition in PHP to determine the same as in Python:

$name = ' Zhang San '; $isMarry = ' TRUE '; if ($isMarry) {echo $name. " Married "}

Answer output :

Zhang San married

We can also use the logical operator : Boolean with (and) Boolean or (or) Boolean not (not) to establish a Boolean type expression:

And: Boolean with If A is false A and B returns False ( short-circuit operation : If the value of a is false when a logical operation is not performed B is worthwhile ) Otherwise he calculates the value of B Special: It's true, the rest is false.

Or: Boolean or if A is false then B-value calculation if A is true then the same short-circuit operation Characteristics: True or False is False

Not: Boolean non if A=true returns False if A=false returns True feature: True for false false

comparison operator (= =) : Indicates whether two values are equal

Next we create a Boolean-type expression:

#企业判断某个人是否是老员工price = 3200;type = "Dollars" years = "AA" If the salary is greater than 3000 and the wage type is USD and does not fall under the entry 2 years or the salary is greater than 3200, the person is the old employee if price > 3 and type = = "Dollars" and not (years<2 or price>3200):p rint (' This man is an old employee ')

Answer output :

This guy's an old employee.

Logic Operators can also be used to make logical judgments in PHP:

and (Logical AND): general use of symbols && representations ( high priority ) can also use and features: If $a and $b are true to indicate true

or (logical OR): general use of symbols | | Indicate ( high priority ) you can also use the or feature: if $ A and $b have a true return True

Logical non: Use symbols ! Indicates a feature: True when the return false value is false when a true

comparison operator (= =) Same as Python, indicates whether two values are equal

The code is as follows:

$price = 3200; $type = ' dollars '; $year = 5;if ($price >3000 && $type = = ' dollars ' &&! $year <2 | | $price >3200) {echo ' This person is an old employee ';}

Answer output :

This guy's an old employee.

There are no specialized branch statements in python that switch case is used to judge multiple values but can be judged using the Elif statement :

Today = 3;if Today = = 1:str = ' It's Monday '; elif now ==2:str = ' today is Tuesday '; Elif Day ==3:str = ' It's Wednesday '; elif today = = 4:str is Thursday '; else:str = ' Today is Friday ';p rint (str);

Answer output :

Today is Wednesday

In PHP, you can use the Switch branch statement to determine multiple values of a variable:

 $today  = 3;switch ($today) {    case 1:        $str   =  ' Today is Monday ';     break;     case 2:      $str   =  ' Today is Tuesday ';      break;    case 3:      $str   =  ' Today is Wednesday ';      break;    case 4:     $ str  =  ' Today is Thursday ';     break;    case 5:       $str   =  ' Today is Friday ';     break;     default:       $str   =  ' Today is the weekend ';   //default: As long as the value is not equal to 1 , the 2,3,4,5 will enter into this inside}echo  $str; 

Answer output :

Today is Wednesday

In Python, the in operator is usually used to determine whether a value is contained in another object and it also returns TRUE or false

The Boolean data type has a value of two:true means True false represents false

Summarize:

Boolean AND and Boolean or or Boolean non-not

|| Represents logic or ! Represents logical non-

3,python if you want to determine the different values of a variable to make corresponding processing using if:elif:else: php uses switch{case:default:}

4, comparison operator = = Determines whether two values are equal

5, in to determine if an object belongs to

6, Boolean value: true False

This article is from the "Hong Dachun Technical column" blog, please be sure to keep this source http://hongdachun.blog.51cto.com/9586598/1759046

Conditional statements, branch statements, and logical and comparison operators in Python