How does logical or work

In the end, we have a plain value-to-boolean conversion. The precedence of NOT! The call to alert does not return a value. Or, in other words, it returns undefined. Write an if condition to check that age is between 14 and 90 inclusively. Write an if condition to check that age is NOT between 14 and 90 inclusively. Hint: passing an empty input to a prompt returns an empty string ''.

Pressing ESC during a prompt returns null. Note the vertical indents inside the if blocks. They are technically not required, but make the code more readable.

We want to make this open-source project available for people all around the world. Tutorial map. For instance:. Tasks What's the result of OR? Well, you have to start simple. Assume that the number 1 is true, and 0 is false. The statements you listed above work in a similar way. Improve this answer. Kirk Backus Kirk Backus 4, 4 4 gold badges 29 29 silver badges 51 51 bronze badges. Sign up or log in Sign up using Google. Sign up using Facebook. Sign up using Email and Password.

Post as a guest Name. Email Required, but never shown. It may be a solid vertical line on some keyboards and show as a solid vertical line on some print fonts. This expression has two relational operators and one logical operator. We can say this in English as: It is true that six is greater than four and that two is less than or equal to fourteen. When forming logical expressions programmers often use parentheses even when not technically needed to make the logic of the expression very clear.

Consider the above complex Boolean expression rewritten:. Most programming languages recognize any non-zero value as true. Mixing up these operators will lead to compilation errors in your program.

June 22, 5 min read. Udacity Team. Relational Operators Relational operators, as briefly mentioned above, operate on variables with specific values and yield a Boolean result. Logical Operators Logical operators operate only on Boolean values or expressions like relational operators that return Boolean values and yield a Boolean result of their own. The Truth Table of Logical Operations No matter how extensive a logical expression, all boil down to a binary true or false value when evaluated.

Bitwise Operators Versus Logical Operators Bitwise operators look and function similarly to logical operators but operate solely on integer-type values and not Booleans. View All Posts by Udacity Team. Popular Nanodegrees. Programming for Data Science with Python. Data Scientist Nanodegree. Self-Driving Car Engineer. Data Analyst Nanodegree.