How do I check if each of 3 variables are the empty string?

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I have 3 input fields with text. I want to use an if statement with logical operators to check if any of the input fields are blank, but I can't use or(||) for the 3 variables.

What is the right way to use logical operators?

let name = $("#name").val();
let email = $("#email).val();
let color = $("#color).val();

if(name == '' && ( email == '' || color == '') {
  console.log("please complete form");
 }
else {
//submit data
}

the code works as desired if I leave the name field blank, but because name is true the if statement accepts it. How can I make it so the if statement checks if any of the input fields are blank?


Use || for each:

if(name === '' || email === '' || color === '') {

You don't need the () groupings because the order of operations doesn't matter - you just want to see if any of the tests succeed.

Note that strict equality comparison (===) is pretty much always preferable over abstract equality comparison (==).

Because .val() always returns a string, and you want to check against the empty string, you could just check whether the value is truthy or not, if you wanted:

if(!name || !email || !color) {

Checking if multiple variables is not null, undefined or empty in an , Because if(variable) ignores any falsy value, this will work for you if(variable && variable2 && variable3). The following values are always falsy  Empty strings are "falsy" which means they are considered false in a Boolean context, so you can just use not string. example string = "" if not string: print "Empty String!" Output. This will give the output: Empty String! Example. If your string can have whitespace and you still want it to evaluate to false, you can just strip it and check again.


An empty string is considered 'falsy' meaning it is interpreted as false when using logical operators. Using that knowledge combined with the ! (not) operator, we can do this:

if(!name || !email || !color) {
  console.log("please complete form");
}

That condition, in plain English, means something like "if not name or not email or not color"

Machine Learning Proceedings 1990: Proceedings of the Seventh , Let |S| denote the number of elements in set S. A (string) pattern is a non-null string A pattern p is called k-occurrence if each variable in p occurs at most k times. Since we can check whether two patterns are the same up to variable naming, in the 3 Learning Patterns from Positive and Negative Examples 3.1 Positive  The advantage of this method compared to IsNullOrEmpty is that IsNullOrWhiteSpace will check for ALL THREE conditions we’ve discussed so far (null, empty string, or a string consisting of white space). So if you indeed want to check for all three of these cases, you can do so with one test:


You had a syntax error (forgot a parenthesis in the if statement).

let name = $("#name").val();
let email = $("#email).val();
let color = $("#color).val();

if(name == '' && ( email == '' || color == '')) {
  console.log("please complete form");
 }
else {
//submit data
}

Python Programming: Problem Solving, Packages and Libraries, Note that a variable named myChar is used to hold the value of each of these '​bird' is a local variable, while birds is a list consisting of three items, that is, Empty string to which non-space characters of s1 will be added for x in s1: 6 if (x != Before adding the characters, they are tested to check that they are not white​  I have 3 input fields with text. I want to use an if statement with logical operators to check if any of the input fields are blank, but I can't use or(||) for the 3 variables.


Elementary Standard ML, (fn x => ((fn x => 2*x) 3)+x)4 Here, the outer bound variable x is in +x in the value (c) replaced all occurrences of the bound variable in the function's body with the If the function has a string argument then check that it works with the empty  Its most basic use is compute s2 = string(s1,f1). where s2 is a string variable, s1 is a numeric variable or value and f1 is the numeric format to be used. With regard to our test data, the syntax below shows how to convert numeric_1 into (previously created) string_3.


How To Check for an Undefined/Null/Empty String - Better , Determine what is valid and use duck-typing to check for all three. Jonathan Hsu. Follow. Nov 28, 2019 · 3 min read. Photo by Aaron Burden on Unsplash Let's start by clarifying the fact that undefined, null, and empty string are similar yet ultimately different. Similarly, the data type of an initialized variable is “​undefined”. Checking if a string is NULL or EMPTY is very common requirement in Powershell script. If we do not checked that we will get some unwanted results when we try to perform some operation on that string variable which is empty or null. The following method is used to check if a string is NULL or empty.


empty - Manual, Determine whether a variable is considered to be empty. A variable is echo '$​var is either 0, empty, or not set at all'; } // Evaluates as PHP 5.4 changes how empty() behaves when passed string offsets. <?php 3=> is empty 4=>Array is  But we can test with string.Empty in if-statements. If. Part 1: We assign to string.Empty. This is mostly equivalent to "". We test the variable against the constant "", which returns true. Part 2: The program tests the Length of the Empty string. Its length is 0, so the string Empty is printed. Console. Part 3: Here we use a switch statement