本文给大家分享js实现点击按钮字体放大缩小实例代码，代码简单易懂，需要的朋友参考下吧

具体代码如下所示：

<style>

.bb{color:red;}

.cc{color:green;}

.chapter {font-size: 1.5em;}

.normal{font-size:12px;}

.hidden{display:none;}

</style>

<script>

$(document).ready(function() {

$('div.aa').addClass('bb');

$('a[href^="http:"]').addClass('cc');

//$('#switcher-large').on('click',function(){

// $('div.large').addClass('chapter'); 

//});

$('#switcher-large').click(function(){ 

$('div.large').toggleClass('chapter');

$(this).toggleClass('bb'); 

});

//$('#switcher').click(function(){//点击按钮增加（移除）样式（toggleClass方法）

//$('#switcher button').toggleClass('hidden');

//})

//字体的放大缩小

var $biger = $('div.large');

var num = parseFloat($biger.css('fontSize')); 

$('#switcher-bigger').click(function(){ 

num=num*1.4;

$biger.css('fontSize',num+'px');

});

$('#switcher-small').click(function(){

num=num/1.4;

$biger.css('fontSize',num+'px');

});

});

</script>

<div id="switcher" class="switcher">

<h3>Style Switcher</h3>

<button id="switcher-default"> Default </button>

<button id="switcher-hidden">Narrow hidden</button>

<button id="switcher-large">Large Print</button>

<button id="switcher-bigger">switcher-bigger</button>

<button id="switcher-small">switcher-small</button>

</div>

<div class="large">

<p>....</p>

<p>....</p>

<p>....</p>

<p>....</p>

</div>

关于JavaScript实现点击按钮字体放大、缩小的相关知识就给大家介绍这么多，希望对大家有所帮助！