The best way to check if an array is empty in JavaScript is by using the Array.isArray() method (ES5+) and array's length property together like so: // ES5+ if (!Array.isArray(array) || !array.length) { /
In the first example, we check if the value has a type ofstring. If it does, we return the result of calling theslice, otherwise, we return an empty string. In the second example, we check if the value is an array using theArray.isArray()method. If the value is an array, we re...
JavaScript is an object oriented dynamic language; it has types and operators, core objects, and methods. Its syntax comes from the Java and C languages, so many structures from those languages apply to JavaScript as well. One of the key differences is that JavaScript does not have classes; ...
One other special case is made forclassattributes: if the attribute value is strictly JavaScript (no static parts to it) and is an array, it is automatically converted to a space-separated string with only truthy values included. Example: ...
is.empty(value:array|object|string) Checks if the given value is empty. is.existy(value:any) Checks if the given value is existy. (not null or undefined) is.truthy(value:any) Checks if the given value is truthy. (existy and not false) is.falsy(value:any) Checks if the given valu...
Unwinding on a nonexistent property or a property whose value is not an array returns an empty array.Example:F.unwind('b', [{ a: true, b: [1, 2] }]) //=> [{ a: true, b: 1 }, { a: true, b: 2 }]unwindArrayk -> [{ k: [a, b] }] -> [{ k: a }, { k: b...
In the following program, we are passing "1/0" as an argument to the isFinite() method to determine whether the result of it, is a finite number or not.Open Compiler JavaScript isFinite() Method document.write("Result of 1/0 is finite number or not? = ", Number.isFinite(1...
We can also check if a variable stores a truthy value. Truthful values are all values that are not false. Falsy values in JavaScript are:undefined,null,false, ,0,""(empty string),NaN(not a number). import{useEffect, useState}from'react'; ...
JavaScript Falsy Values:null, false, 0 undefined, NaN, and “” (this last item is an empty string). — Note thatInfinity, which is a special number likeNaN,is truthy; it is not falsy, while NaN is falsy. JavaScript Truthy Values:Anything other than the falsy values. ...
As one of the Handlebars developers advised: it is best to check for the length property of the variable, to catch cases where an array might be empty: {{#if userActive.length}} Welcome, {{firstName}} {{/if}} As noted above, theifhelper does not evaluate conditional logic, so we...