Ternary operator

Updated: 04/26/2017 by Computer Hope

The ternary operator is an operator that exists in a number of programming languages, which takes three operands rather than the typical one or two that most operators use. It provides a way to shorten a simple if else block. For example, consider the below JavaScript code.

var num = 4, msg = "";
if (num === 4) {
  msg = "Correct!";
}
else {
  msg = "Incorrect!";
}
alert(msg);

If the num variable is equal to 4, then the user will get a "Correct!" message. Otherwise, the user receives an "Incorrect!" message. With this type of comparison, you can shorten the code using the ternary operator. Below is an example of how it works.

variable_name = (condition) ? value_if_true : value_if false;

A ternary operator allows you to assign one value to the variable if the condition is true, and another value if the condition is false.

The if else block example from above could now be written as shown in the example below.

var num = 4, msg = "";
msg = (num === 4) ? "Correct!" : "Incorrect!";
alert(msg);

In many cases, this can make the assignment of a value to a variable easier to see, since it is contained on a single line instead of an if else block.

Operator, Programming terms