is-empty – w3toppers.com

How to find whether or not a variable is empty in Bash

In Bash at least the following command tests if $var is empty: if [[ -z “$var” ]]; then # $var is empty, do what you want fi The command man test is your friend.

How to check if a file is empty in Bash?

Misspellings are irritating, aren’t they? Check your spelling of empty, but then also try this: #!/bin/bash -e if [ -s diff.txt ]; then # The file is not-empty. rm -f empty.txt touch full.txt else # The file is empty. rm -f full.txt touch empty.txt fi I like shell scripting a lot, but one disadvantage of … Read more

Recursively remove empty elements and subarrays from a multi-dimensional array

Try using array_map() to apply the filter to every array in $array: $array = array_map(‘array_filter’, $array); $array = array_filter($array); Demo: http://codepad.org/xfXEeApj

How do I check for an empty/undefined/null string in JavaScript?

Empty string, undefined, null, … To check for a truthy value: if (strValue) { // strValue was non-empty string, true, 42, Infinity, [], … } To check for a falsy value: if (!strValue) { // strValue was empty string, false, 0, null, undefined, … } Empty string (only!) To check for exactly an empty string, … Read more

Detect if an input has text in it using CSS — on a page I am visiting and do not control?

You can use the :placeholder-shown pseudo class. Technically a placeholder is required, but you can use a space instead. input:not(:placeholder-shown) { border-color: green; } input:placeholder-shown { border-color: red; } <input placeholder=”Text is required” /> <input placeholder=” ” value=”This one is valid” /> <input placeholder=” ” />