SOURCE

function isNumber(value) {
  let patrn = /^[0-9]+$/;
  return patrn.test(value);
}

function init() {
  let oriStr = prompt('输入') || '';
  let sum = 0,
  mean = 0;
  console.log('lkdf');
  let str = oriStr.trim(); // 去掉前后空格
  if (str.length === 0) {
    alert('空字符串');
    return;
  }
  let strArr = str.split(' ');
  console.log('数组:' + strArr + ' 长度:' + str.length);

  let results = []; //放有效的数字
  for (let i = 0; i < strArr.length; i++) {
    let s = strArr[i];

    if (isNumber(s)) { //判断是否数字
      console.log(s);
      results.push(parseInt(s));
    } else {
      if (s === '') { //如果是空字符串
        let count = 2; //有n个空字符串，说明有n+1个空格,所以是2
        while (true) {
          if (strArr[++i] === '') {
            count++;
          } else {
            break;
          }
        }
        alert('错误:' + count + '个空格');
        return;
      } else {
        //有时候s的第一段确实是数字：'7 1. 2'，比如'1.'不是一个数字，但1是，所以要找到'.'
        let i = 0;
        while (isNumber(s[i])) { 
          i++;
        }
        alert('错误:' + s[i]); //输出第一个字符
        return;
      }
    }
  }
  console.log(results);
  results.forEach(function(val) {
    sum += val;
  });
  mean = sum / results.length;
  alert('sum:' + sum + '\n' + 'mean:' + mean)
}

// init();

<div>sorry,babe</div>
<div>I love you</div>
<div class="heart"></div>

div {
  font-size: 50px;
  font-weight: bold;
  text-align: center;
}

.heart{
	position:relative;
	width:200px;
	height:200px;
	background-color: #d31145;
	margin:100px auto; 
	transform: rotate(45deg);
	-webkit-transform: rotate(45deg);
	moz-transform: rotate(45deg);
	-o-transform: rotate(45deg);
	-ms-transform: rotate(45deg);
}
.heart:before,.heart:after{
  position:absolute;
  content:'';
  width:200px;
  height:200px;
  display:block;
  border-radius:50%;
  background-color: #d31145; 
}
.heart:before{
	left:-100px;
	bottom:0;
}
.heart:after{
	top:-100px;
	right:0;
}