Conditionals: Difference between revisions

Latest revision as of 14:32, 11 October 2021

Programming basics^[1]

Programs generally run sequentially, starting from the first instruction and then moving to the next instruction, in a step-by-step process. A computer will read line one, execute line one, and then go to line two, for example. It is common to include conditional statements to decide if a program should "do something else" if a specific condition is true or false.

A conditional statement evaluates an expression and executes instructions depending on the outcome of the evaluation. Conditionals depend on operators to evaluate if an expression is true or false. A condition and selection are not the same thing. A condition asks a question. A selection processes the answer.

With gratitude to and permission from Stephen Hughes (Coe College) and Philip East (University of Northern Iowa)^[2], The list below is an example of types of conditional questions. You should start thinking about conditions in plain english before you start thinking about operators.

Match
Threshold
Range
One-of
Not-match
Not one of
All of
Some of
Eligible

Conditional operators[edit]

Please see this link for conditional operators

Conditional code sample[edit]

# this file helps us to understand conditionals in Python.
# what do you think the output will be when you execute these instructions? 

a = 5
b = "bar"

if a == 5:
    print("Yes, the variable a has been assigned to the value 5.")
else:
    print("No, the variable a has not been assigned to the value 5.")


# what do you think the output will be when you execute these instructions? 

a = 5
b = "bar"

if b == "foo":
     print("yes, the variable b has been assigned the value foo")
else:
     print("no, the variable b has been assigned to some other value than foo.")

Multiple conditionals code sample[edit]

# this file helps us to understand multiple conditionals in Python.
# what do you think the output will be when you execute these instructions? 

a = 5
b = "bar"

if (a == 5 and b == "bar"):
    print("both conditions are true.")
else:
    print("one or both of the conditions are false")


# what do you think the output will be when you execute these instructions? 

a = 5
b = "bar"

if (a == 5 or b == "bar"):
    print("both conditions are true.")
else:
    print("one or both of the conditions are false")

Conditional code sample with lists[edit]

# this file helps us to understand conditionals in Python.
# what do you think the output will be when you execute these instructions? 

myList = ["foo","bar","baz"]

if "foo" in myList:
     print("Foo is in the list")
else:
     print("Foo is not in list")


# what do you think the output will be when you execute these instructions? 

myList = ["foo","bar","baz"]

if "bar" not in myList:
     print("bar is in the list")
else:
     print("bar is not in list")

Some videos[edit]

References[edit]

[1] ttp://www.flaticon.com/

[2] ttp://www.cs.uni.edu/~east/

[1]

[2]

@@ Line 1: / Line 1: @@
 [[file:arrows.png|right|frame|Programming basics<ref>http://www.flaticon.com/</ref>]]
-A conditional statement evaluates an expression and executes instructions depending on the outcome of the evaluation. Conditionals depend on [[operators]] to evaluate if an expression is true or false. Can you think where else you have seen how computers process logic?
+Programs generally run sequentially, starting from the first instruction and then moving to the next instruction, in a step-by-step process. A computer will read line one, execute line one, and then go to line two, for example.
+It is common to include conditional statements to decide if a program should "do something else" if a specific condition is true or false.
-An example of a simple conditional in PHP can be found below:
+A conditional statement evaluates an expression and executes instructions depending on the outcome of the evaluation. Conditionals depend on [[operators]] to evaluate if an expression is true or false. A condition and selection are not the same thing. A condition asks a question. A selection processes the answer.
-<syntaxhighlight lang="php"  line>
+With gratitude to and permission from Stephen Hughes (Coe College) and Philip East (University of Northern Iowa)<ref>http://www.cs.uni.edu/~east/</ref>, The list below is an example of types of conditional questions. You should '''start''' thinking about conditions in plain english before you start thinking about [[operators]].
-<?php
+* Match
-# this file  is used to teach the VERY BASICS of conditions in php
+* Threshold
+* Range
+* One-of
+* Not-match
+* Not one of
+* All of
+* Some of
+* Eligible
-$secret_number = 54;
+== Conditional operators ==
-$player_guess = 54;
+* [https://computersciencewiki.org/index.php/Operators#Comaprison_operators Please see this link for conditional operators]
-if ($player_guess == $secret_number) {
-     echo "You guessed it!";
-     } elseif ($player_guess >= $secret_number) {
-     echo "a bit high...";
-     } elseif ($player_guess <= $secret_number) {
-     echo "a bit low...";
-      }
+== Conditional code sample ==
-?>
+<syntaxhighlight lang="python">
+# this file helps us to understand conditionals in Python.
+# what do you think the output will be when you execute these instructions?
+a = 5
+b = "bar"
+if a == 5:
+    print("Yes, the variable a has been assigned to the value 5.")
+else:
+    print("No, the variable a has not been assigned to the value 5.")
+# what do you think the output will be when you execute these instructions?
+a = 5
+b = "bar"
+if b == "foo":
+     print("yes, the variable b has been assigned the value foo")
+else:
+      print("no, the variable b has been assigned to some other value than foo.")
+</syntaxhighlight>
+== Multiple conditionals code sample ==
+<syntaxhighlight lang="python">
+# this file helps us to understand multiple conditionals in Python.
+# what do you think the output will be when you execute these instructions?
+a = 5
+b = "bar"
+if (a == 5 and b == "bar"):
+    print("both conditions are true.")
+else:
+    print("one or both of the conditions are false")
+# what do you think the output will be when you execute these instructions?
+a = 5
+b = "bar"
+if (a == 5 or b == "bar"):
+    print("both conditions are true.")
+else:
+    print("one or both of the conditions are false")
+</syntaxhighlight>
+== Conditional code sample with lists ==
+<syntaxhighlight lang="python">
+# this file helps us to understand conditionals in Python.
+# what do you think the output will be when you execute these instructions?
+myList = ["foo","bar","baz"]
+if "foo" in myList:
+     print("Foo is in the list")
+else:
+     print("Foo is not in list")
+# what do you think the output will be when you execute these instructions?
+myList = ["foo","bar","baz"]
+if "bar" not in myList:
+     print("bar is in the list")
+else:
+     print("bar is not in list")
 </syntaxhighlight>
-== A video ==
-This video references the C programming language and scratch, but the ideas about conditionals are excellent. In the case of conditionals, PHP and C share similar syntax (but not exact).
+== Some videos ==
 <html>
-<iframe width="560" height="315" src="https://www.youtube.com/embed/kTnp_-nyocs" frameborder="0" allowfullscreen></iframe>
+<iframe width="560" height="315" src="https://www.youtube.com/embed/ZgB0Wp-fShk" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>
 </html>
-== Standards ==
-* Define the terms: variable, constant, operator, object.
+<html>
+<iframe width="560" height="315" src="https://www.youtube.com/embed/D5fSbCKobko" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>
+</html>
+<html>
+<iframe width="560" height="315" src="https://www.youtube.com/embed/m2Ux2PnJe6E" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>
+</html>
 == See Also ==
-* [[Conditionals in php]]
 * [[Operators]]