if..elif..elseThe if-elif-else statement is used to conditionally execute a statement or a block of statements. Conditions can be true or false, execute one thing when the condition is true, something else when the condition is false. Show
if statementThe Python if statement is same as it is with other programming languages. It executes a set of statements conditionally, based on the value of a logical expression. Here is the general form of a one way if statement. Syntax: if expression : statement_1 statement_2 .... In the above case, expression specifies the conditions which are based on Boolean expression. When a Boolean expression is evaluated it produces either a value of true or false. If the expression evaluates true the same amount of indented statement(s) following if will be executed. This group of the statement(s) is called a block. if .. else statementIn Python if .. else statement, if has two blocks, one following the expression and other following the else clause. Here is the syntax. Syntax: if expression : statement_1 statement_2 .... else : statement_3 statement_4 .... In the above case if the expression evaluates to true the same amount of indented statements(s) following if will be executed and if the expression evaluates to false the same amount of indented statements(s) following else will be executed. See the following example. The program will print the second print statement as the value of a is 10.
Output: Value of a is 10 Flowchart: if .. elif .. else statementSometimes a situation arises when there are several conditions. To handle the situation Python allows adding any number of elif clause after an if and before an else clause. Here is the syntax. Syntax: if expression1 : statement_1 statement_2 .... elif expression2 : statement_3 statement_4 .... elif expression3 : statement_5 statement_6 .................... else : statement_7 statement_8 In the above case Python evaluates each expression (i.e. the condition) one by one and if a true condition is found the statement(s) block under that expression will be executed. If no true condition is found the statement(s) block under else will be executed. In the following example, we have applied if, series of elif and else to get the type of a variable.
Output: Type of the variable is Complex Flowchart: Nested if .. else statementIn general nested if-else statement is used when we want to check more than one conditions. Conditions are executed from top to bottom and check each condition whether it evaluates to true or not. If a true condition is found the statement(s) block associated with the condition executes otherwise it goes to next condition. Here is the syntax : Syntax: if expression1 : if expression2 : statement_3 statement_4 .... else : statement_5 statement_6 .... else : statement_7 statement_8 In the above syntax expression1 is checked first, if it evaluates to true then the program control goes to next if - else part otherwise it goes to the last else statement and executes statement_7, statement_8 etc.. Within the if - else if expression2 evaluates true then statement_3, statement_4 will execute otherwise statement_5, statement_6 will execute. See the following example.
Output : You are eligible to see the Football match. Tic kit price is $20 In the above example age is set to 38, therefore the first expression (age >= 11) evaluates to True and the associated print statement prints the string "You are eligible to see the Football match". There after program control goes to next if statement and the condition ( 38 is outside <=20 or >=60) is matched and prints "Tic kit price is $12". Flowchart: Use the and operator in an if statement
Output: x is False or y is False or both x and y are False Use the in operator in an if statement
Output: jQuery Tutorial jQuery Tutorial Write an if-else in a single line of code
Output: 150 21.428571428571427 Define a negative ifIf a condition is true the not operator is used to reverse the logical state, then logical not operator will make it false.
Output: 20 the value of x different from 50 Test your Python skills with w3resource's quiz Why do most programmers indent the conditionally executed statements in an if statement?By indenting the conditionally executed statement you are causing it to stand out visually. It is useful for human readers.
What is the difference between an if statement an IF ELSE statement and an IF ELSE IF statement quizlet?. In an if/else if statement, the conditions are tested until one is found to be true. The conditionally executed statement(s) are executed and the program exits the if/else if statement. In a series of if statements, all of the if statements execute and test their conditions because they are not connected.
Does else execute after if?With the if statement, a program will execute the true code block or do nothing. With the if/else statement, the program will execute either the true code block or the false code block so something is always executed with an if/else statement.
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