JavaScript 求和（字符串转换成数组、for循环求和）

￡神魔★判官ぃ 2021-11-22 14:46 344阅读 0赞

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDc5NzE4Mg_size_16_color_FFFFFF_t_70]

<!DOCTYPE html>
    <html>
    	<head>
    		<meta charset="utf-8">
    		<title>数组求和与字符串求和</title>
    		<style type="text/css">
    			#case { 
    				width: 40%;
    				height: 100px;
    				margin: 50px auto;
    			}
    			input { 
    				width: 60%;
    				height: 30px
    			}
    			p:last-child { 
    				background: #00FFFF;
    				width: 50%;
    				height: 50px;
    				text-align: center;
    				line-height: 50px;
    				margin: 20px auto;
    				cursor: pointer;
    			}
    		</style>
    		<script type="text/javascript">
    			window.onload = function() { 
    				var oInput = document.getElementsByTagName("input")[0];
    				var oBtn = document.getElementsByTagName("p")[0];
    				//当从表单中输入时,将不属于数字或者"，"的全部转换为空
    				oInput.onkeyup=function(){ 
    					this.value=this.value.replace(/[^(\d)|(,)]/,"")
    				}
    				oBtn.onclick = function() { 
    					var arr = oInput.value.split(","); //转换成数组
    					var sum = 0;
    					for (var item, i = 0; item = arr[i++];) { 
    						sum += parseInt(item); //数组求和（转换成整数）
    					}
    					alert(sum)
    				}
    
    
    			}
    		</script>
    	</head>
    	<body>
    		<div id="case">
    			<form>
    				<input type="text" value="1,2,3,4" id="demo" />（以逗号隔开）
    			</form>
    			<p>点击求和</p>
    		</div>
    
    	</body>
    </html>

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