ES6Number的处理
<h4>数字判断和转换</h4>
<ul>
<li>数字验证 Number.isFinite(xx)
<blockquote>
<p>不管是整型还是浮点型都会返回True</p>
</blockquote></li>
</ul>
<pre><code class="language-javasript">let a= 232;
console.log(Number.isFinite(a));//true
console.log(Number.isFinite('hello'));//false
console.log(Number.isFinite(NaN));//false
console.log(Number.isFinite(undefined));//false</code></pre>
<ul>
<li>NaN的验证：Number.isNaN()
<blockquote>
<p>NaN是特殊非数字，可以对NaN来进行验证</p>
</blockquote></li>
</ul>
<pre><code class="language-javascript">console.log(Number.isNaN(NaN)) //true
console.log(Number.isFinite("null"))//false</code></pre>
<ul>
<li>整数的验证 Number.(xx)</li>
</ul>
<pre><code class="language-javascript">console.log(Number.isInteger('99'))//false
console.log(Number.isInteger(Number('99')))//true</code></pre>
<ul>
<li>整数转换Number.parseInt()和浮点型转换Number.parseFloat(xxx)</li>
</ul>
<pre><code class="language-javascript">//Number.parseInt()
console.log(Number.parseInt('99')) //99
console.log(Number.parseInt('99.99'))//99
console.log(Number.parseInt(99))//99
console.log(Number.parseInt('哈哈'))//NaN
//Number.parseFloat
console.log(Number.parseFloat(99.99))//99.99
console.log(Number.parseFloat(99))//99
console.log(Number.parseFloat("99"))//99
</code></pre>
<ul>
<li>取值范围</li>
</ul>
<pre><code class="language-javascript">//最大取值范围
consolec .log(Number.MAX_SAFE_INTEGER);
//最小取值范围
console.log(Number.MIN_SAFE_INTEGER);</code></pre>