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<!DOCTYPE html> <html> <head> <title>_.function.predicates.js.md</title> <meta http-equiv="content-type" content="text/html; charset=UTF-8"> <meta name="viewport" content="width=device-width, target-densitydpi=160dpi, initial-scale=1.0; maximum-scale=1.0; user-scalable=0;"> <link rel="stylesheet" media="all" href="docco.css" /> </head> <body> <div id="container"> <div id="background"></div> <ul id="jump_to"> <li> <a class="large" href="javascript:void(0);">Jump To …</a> <a class="small" href="javascript:void(0);">+</a> <div id="jump_wrapper"> <div id="jump_page_wrapper"> <div id="jump_page"> <a class="source" href="_.array.builders.js.html"> _.array.builders.js.md </a> <a class="source" href="_.array.selectors.js.html"> _.array.selectors.js.md </a> <a class="source" href="_.collections.walk.js.html"> _.collections.walk.js.md </a> <a class="source" href="_.function.arity.js.html"> _.function.arity.js.md </a> <a class="source" href="_.function.combinators.js.html"> _.function.combinators.js.md </a> <a class="source" href="_.function.iterators.js.html"> _.function.iterators.js.md </a> <a class="source" href="_.function.predicates.js.html"> _.function.predicates.js.md </a> <a class="source" href="_.object.builders.js.html"> _.object.builders.js.md </a> <a class="source" href="_.object.selectors.js.html"> _.object.selectors.js.md </a> <a class="source" href="_.util.existential.js.html"> _.util.existential.js.md </a> <a class="source" href="_.util.operators.js.html"> _.util.operators.js.md </a> <a class="source" href="_.util.strings.js.html"> _.util.strings.js.md </a> <a class="source" href="_.util.trampolines.js.html"> _.util.trampolines.js.md </a> <a class="source" href="index.html"> index.md </a> </div> </div> </li> </ul> <ul class="sections"> <li id="title"> <div class="annotation"> <h1>_.function.predicates.js.md</h1> </div> </li> <li id="section-1"> <div class="annotation"> <div class="pilwrap "> <a class="pilcrow" href="#section-1">¶</a> </div> <h3 id="function-predicates">function.predicates</h3> <blockquote> <p>Functions which return whether the input meets a condition.</p> </blockquote> <hr> </div> </li> <li id="section-2"> <div class="annotation"> <div class="pilwrap "> <a class="pilcrow" href="#section-2">¶</a> </div> <h4 id="isassociative">isAssociative</h4> <p><strong>Signature:</strong> <code>isAssociative(value:Any)</code></p> <p>Returns a boolean indicating whether or not the value is an associative object. An associative object is one where its elements can be accessed via a key or index (e.g. arrays, <code>arguments</code>, objects).</p> <pre><code class="lang-javascript">_.isAssociative([<span class="hljs-string">"Athens"</span>, <span class="hljs-string">"Sparta"</span>]); <span class="hljs-comment">// => true</span> _.isAssociative(<span class="hljs-number">42</span>); <span class="hljs-comment">// => false</span> </code></pre> <hr> </div> </li> <li id="section-3"> <div class="annotation"> <div class="pilwrap "> <a class="pilcrow" href="#section-3">¶</a> </div> <h4 id="isdecreasing">isDecreasing</h4> <p><strong>Signature:</strong> <code>_.isDecreasing(values:Any...)</code></p> <p>Checks whether the arguments are monotonically decreasing values (i.e. whether each argument is less than the previous argument.)</p> <pre><code class="lang-javascript">_.isDecreasing(<span class="hljs-number">3</span>, <span class="hljs-number">2</span>, <span class="hljs-number">1</span>); <span class="hljs-comment">// => true</span> _.isDecreasing(<span class="hljs-number">15</span>, <span class="hljs-number">12</span>, <span class="hljs-number">2</span>); <span class="hljs-comment">// => true</span> _.isDecreasing(<span class="hljs-number">2</span>, <span class="hljs-number">3</span>); <span class="hljs-comment">// => false</span> </code></pre> <hr> </div> </li> <li id="section-4"> <div class="annotation"> <div class="pilwrap "> <a class="pilcrow" href="#section-4">¶</a> </div> <h4 id="iseven">isEven</h4> <p><strong>Signature:</strong> <code>_.isEven(value:Any)</code></p> <p>Checks whether the value is an even number.</p> <pre><code class="lang-javascript">_.isEven(<span class="hljs-number">12</span>); <span class="hljs-comment">// => true</span> _.isEven(<span class="hljs-number">3</span>); <span class="hljs-comment">// => false</span> _.isEven({}); <span class="hljs-comment">// => false</span> </code></pre> <hr> </div> </li> <li id="section-5"> <div class="annotation"> <div class="pilwrap "> <a class="pilcrow" href="#section-5">¶</a> </div> <h4 id="isfloat">isFloat</h4> <p><strong>Signature:</strong> <code>_.isFloat(value:Any)</code></p> <p>Checks whether the value is a “float.” For the purposes of this function, a float is a numeric value that is not an integer. A numeric value may be a number, a string containing a number, a <code>Number</code> object, etc.</p> <p><strong>NOTE:</strong> JavaScript itself makes no distinction between integers and floats. For the purposes of this function both <code>1</code> and <code>1.0</code> are considered integers.</p> <pre><code class="lang-javascript">_.isFloat(<span class="hljs-number">1.1</span>); <span class="hljs-comment">// => true</span> _.isFloat(<span class="hljs-number">1</span>); <span class="hljs-comment">// => false</span> _.isFloat(<span class="hljs-number">1.0</span>); <span class="hljs-comment">// => false</span> _.isFloat(<span class="hljs-string">"2.15"</span>); <span class="hljs-comment">// => true</span> </code></pre> <hr> </div> </li> <li id="section-6"> <div class="annotation"> <div class="pilwrap "> <a class="pilcrow" href="#section-6">¶</a> </div> <h4 id="isincreasing">isIncreasing</h4> <p><strong>Signature:</strong> <code>_.isIncreasing(value:Any...)</code></p> <p>Checks whether the arguments are monotonically increasing values (i.e. each argument is greater than the previous argument.)</p> <pre><code class="lang-javascript">_.isIncreasing(<span class="hljs-number">1</span>, <span class="hljs-number">12</span>, <span class="hljs-number">15</span>); <span class="hljs-comment">// => true</span> _.isIncreasing(<span class="hljs-number">1</span>); <span class="hljs-comment">// => true</span> _.isIncreasing(<span class="hljs-number">5</span>, <span class="hljs-number">4</span>); <span class="hljs-comment">// => false</span> </code></pre> <hr> </div> </li> <li id="section-7"> <div class="annotation"> <div class="pilwrap "> <a class="pilcrow" href="#section-7">¶</a> </div> <h4 id="isindexed">isIndexed</h4> <p><strong>Signature:</strong> <code>_.isIndexed(value:Any)</code></p> <p>Checks whether the value is “indexed.” An indexed value is one which accepts a numerical index to access its elements. (e.g. arrays and strings)</p> <p><strong>NOTE:</strong> lodash does not support cross-browser consistent use of strings as array-like values, so be wary in IE 8 when using string objects and in IE7 and earlier when using string literals & objects.</p> <pre><code class="lang-javascript">_.isIndexed(<span class="hljs-string">"Socrates"</span>); <span class="hljs-comment">// => true</span> _.isIndexed({poison: <span class="hljs-string">"hemlock"</span>}); <span class="hljs-comment">// => false</span> </code></pre> <hr> </div> </li> <li id="section-8"> <div class="annotation"> <div class="pilwrap "> <a class="pilcrow" href="#section-8">¶</a> </div> <h4 id="isinstanceof">isInstanceOf</h4> <p><strong>Signature:</strong> <code>_.isInstanceOf(value:Any, constructor:Function)</code></p> <p>Checks whether the value is an instance of the constructor.</p> <pre><code class="lang-javascript">_.isInstanceOf(<span class="hljs-keyword">new</span> <span class="hljs-built_in">Date</span>(), <span class="hljs-built_in">Date</span>); <span class="hljs-comment">// => true</span> _.isInstanceOf(<span class="hljs-string">"Hippocrates"</span>, <span class="hljs-built_in">RegExp</span>); <span class="hljs-comment">// => false</span> </code></pre> <hr> </div> </li> <li id="section-9"> <div class="annotation"> <div class="pilwrap "> <a class="pilcrow" href="#section-9">¶</a> </div> <h4 id="isinteger">isInteger</h4> <p><strong>Signature:</strong> <code>_.isInteger(value:Any)</code></p> <p>Checks whether the value is a numeric integer. A numeric value can be a string containing a number, a <code>Number</code> object, etc.</p> <pre><code class="lang-javascript">_.isInteger(<span class="hljs-number">18</span>); <span class="hljs-comment">// => true</span> _.isInteger(<span class="hljs-string">"18"</span>); <span class="hljs-comment">// => true</span> _.isInteger(<span class="hljs-number">2.5</span>); <span class="hljs-comment">// => false</span> _.isInteger(-<span class="hljs-number">1</span>); <span class="hljs-comment">// => true</span> </code></pre> <hr> </div> </li> <li id="section-10"> <div class="annotation"> <div class="pilwrap "> <a class="pilcrow" href="#section-10">¶</a> </div> <h4 id="isjson">isJSON</h4> <p><strong>Signature:</strong> <code>_.isJSON(value:Any)</code></p> <p>Checks whether the value is valid JSON. <a href="http://www.json.org/">See the spec</a> for more information on what constitutes valid JSON.</p> <p><strong>NOTE:</strong> This function relies on <code>JSON.parse</code> which is not available in IE7 and earlier.</p> <pre><code class="lang-javascript">_.isJSON(<span class="hljs-string">'{ "name": "Crockford" }'</span>); <span class="hljs-comment">// => true</span> _.isJSON({ name: <span class="hljs-string">"Crocket"</span> }); <span class="hljs-comment">// => false</span> </code></pre> <hr> </div> </li> <li id="section-11"> <div class="annotation"> <div class="pilwrap "> <a class="pilcrow" href="#section-11">¶</a> </div> <h4 id="isnegative">isNegative</h4> <p><strong>Signature:</strong> <code>_.isNegative(value:Any)</code></p> <p>Checks whether the value is a negative number.</p> <pre><code class="lang-javascript">_.isNegative(-<span class="hljs-number">2</span>); <span class="hljs-comment">// => true</span> _.isNegative(<span class="hljs-number">5</span>); <span class="hljs-comment">// => false</span> </code></pre> <hr> </div> </li> <li id="section-12"> <div class="annotation"> <div class="pilwrap "> <a class="pilcrow" href="#section-12">¶</a> </div> <h4 id="isnumeric">isNumeric</h4> <p><strong>Signature:</strong> <code>_.isNumeric(value:Any)</code></p> <p>A numeric is something that contains a numeric value, regardless of its type. It can be a string containing a numeric value, exponential notation, a <code>Number</code> object, etc.</p> <pre><code class="lang-javascript">_.isNumeric(<span class="hljs-string">"14"</span>); <span class="hljs-comment">// => true</span> _.isNumeric(<span class="hljs-string">"fourteen"</span>); <span class="hljs-comment">// => false</span> </code></pre> <hr> </div> </li> <li id="section-13"> <div class="annotation"> <div class="pilwrap "> <a class="pilcrow" href="#section-13">¶</a> </div> <h4 id="isodd">isOdd</h4> <p><strong>Signature:</strong> <code>_.isOdd(value:Any)</code></p> <p>Checks whether the value is an odd number.</p> <pre><code class="lang-javascript">_.isOdd(<span class="hljs-number">3</span>); <span class="hljs-comment">// => true</span> _.isOdd(<span class="hljs-number">2</span>); <span class="hljs-comment">// => false</span> _.isOdd({}); <span class="hljs-comment">// => false</span> </code></pre> <hr> </div> </li> <li id="section-14"> <div class="annotation"> <div class="pilwrap "> <a class="pilcrow" href="#section-14">¶</a> </div> <h4 id="isplainobject">isPlainObject</h4> <p><strong>Signature:</strong> <code>_.isPlainObject(value:Any);</code></p> <p>Checks whether the value is a “plain” object created as an object literal (<code>{}</code>) or explicitly constructed with <code>new Object()</code>. Instances of other constructors are <strong>not</strong> plain objects.</p> <pre><code class="lang-javascript">_.isPlainObject({}); <span class="hljs-comment">// => true</span> _.isPlainObject(<span class="hljs-keyword">new</span> <span class="hljs-built_in">Date</span>()); <span class="hljs-comment">// => false</span> _.isPlainObject([]); <span class="hljs-comment">// => false</span> </code></pre> <hr> </div> </li> <li id="section-15"> <div class="annotation"> <div class="pilwrap "> <a class="pilcrow" href="#section-15">¶</a> </div> <h4 id="ispositive">isPositive</h4> <p><strong>Signature:</strong> <code>_.isPositive(value:Any)</code></p> <p>Checks whether the value is a positive number.</p> <pre><code class="lang-javascript">_.isPositive(<span class="hljs-number">21</span>); <span class="hljs-comment">// => true</span> _.isPositive(-<span class="hljs-number">3</span>); <span class="hljs-comment">// => false</span> </code></pre> <hr> </div> </li> <li id="section-16"> <div class="annotation"> <div class="pilwrap "> <a class="pilcrow" href="#section-16">¶</a> </div> <h4 id="issequential">isSequential</h4> <p><strong>Signature:</strong> <code>_.isSequential(value:Any)</code></p> <p>Checks whether the value is a sequential composite type (i.e. arrays and <code>arguments</code>).</p> <pre><code class="lang-javascript">_.isSequential([<span class="hljs-string">"Herodotus"</span>, <span class="hljs-string">"Thucidydes"</span>); <span class="hljs-comment">// => true</span> _.isSequential(<span class="hljs-keyword">new</span> <span class="hljs-built_in">Date</span>); <span class="hljs-comment">// => false</span> </code></pre> <hr> </div> </li> <li id="section-17"> <div class="annotation"> <div class="pilwrap "> <a class="pilcrow" href="#section-17">¶</a> </div> <h4 id="isvaliddate">isValidDate</h4> <p><strong>Signature:</strong> <code>_.isValidDate(value:Any)</code></p> <p>Checks whether the value is a valid date. That is, the value is both an instance of <code>Date</code> and it represents an actual date.</p> <p><span class="label label-danger">Warning:</span> This function does not verify whether the original input to <code>Date</code> is a real date. For instance, <code>new Date("02/30/2014")</code> is considered a valid date because <code>Date</code> coerces that into a representation of 03/02/2014. To validate strings representing a date, consider using a date/time library like [Moment.js.][momentjs]</p> <pre><code class="lang-javascript">_.isValidDate(<span class="hljs-keyword">new</span> <span class="hljs-built_in">Date</span>(<span class="hljs-string">"January 1, 1900"</span>)); <span class="hljs-comment">// => true</span> _.isValidDate(<span class="hljs-keyword">new</span> <span class="hljs-built_in">Date</span>(<span class="hljs-string">"The Last Great Time War"</span>)); <span class="hljs-comment">// => false</span> </code></pre> <hr> </div> </li> <li id="section-18"> <div class="annotation"> <div class="pilwrap "> <a class="pilcrow" href="#section-18">¶</a> </div> <h4 id="iszero">isZero</h4> <p><strong>Signature:</strong> <code>_.isZero(value:Any)</code></p> <p>Checks whether the value is <code>0</code>.</p> <pre><code class="lang-javascript">_.isZero(<span class="hljs-number">0</span>); <span class="hljs-comment">// => true</span> _.isZero(<span class="hljs-string">"Pythagoras"</span>); <span class="hljs-comment">// => false</span> </code></pre> <hr> </div> </li> <li id="section-19"> <div class="annotation"> <div class="pilwrap "> <a class="pilcrow" href="#section-19">¶</a> </div> </div> </li> </ul> </div> </body> </html>