1.7 Conditional Statements -3-¶
Short way: Ternary Operator¶
Task 1: if the student's mark is greater than 60, he/she passes the exam; otherwise, he/she fails.
var mark = 70;
if(mark > 60){
var pass = true;
}else{
var pass = false;
}
console.log(pass);
You will get: true.
Task 2: We re-wrote the code in task 1. Check it out:
var mark = 70;
var pass = mark > 60 ? true : false;
console.log(pass);
You will get: true
What did happen here? mark > 60 ? true : false
is the same as the if
statement in task 1.
Note(1): condition ? successValue : failureValue
is called Ternary Operator or Conditional Operator.
Let's practice more and you will have a better understanding of Ternary Operator.
Task 3: if the value is less than or equal to 30, display "low" in the console; otherwise, display "high".
var value = 50;
if(value <= 30){
console.log('low');
}else{
console.log("high");
}
You will get: high.
Now let's use the ternary operator:
var value = 50;
var result = value <=30 ? "low" : "high";
console.log(result);
you will get: high
Task 4: if the user provided a name
, set the username
to the name
+ 123; otherwise, set the username
to the userEmail
.
var name = "Ali";
var userEmail = "mail@gmail.com";
if(name){
var username = name + 123;
}else{
var username = userEmail;
}
You will get: Ali123.
You can also write:
var name = "Ali";
var userEmail = "mail@gmail.com";
var username = name? name + 123 : userEmail;
You will get: mail@gmail.com
Task 5: if the password is strong, display "great" in the console; otherwise, display "not secure!".
var isStrong = true;
var message = isStrong ? "great" : "not secure!";
console.log(message);
You will get: great
Task 6: if the temperature is greater than 30, the weather is hot; otherwise, it is okay.
var temp = 20;
var weather = temp > 30 ? "Hot" : "Okay";
console.log(weather);
You will get: Okay
Task 7: if the paragraph has more than 500 words, it is a long paragraph; otherwise, it is short.
var wordsCount = 300;
var isLong = wordsCount > 500 ? true : false;
console.log(isLong);
You will get: false
Task 8: if the YouTube video is longer than or equal to 30, display "Good"; otherwise, "Not Bad".
var videoLength = 40;
var msg = videoLength >= 40 ? "Good" : "Not Bad";
console.log(msg);
You will get: Good