js 查找出字符串中出现次数最多的字符

效果

在线演示

HTML

<div id='showStr'>
  
</div>
<div id='showChar'>
  
</div>
<div id='bigStr'>
  
</div>

JS

var str = "sjl;黄sdfsdtyt ;aaaaabbbbb";
var obj = {
    
    };
for(var i = 0;i < str.length;i++){
    
    
  if(!obj[str.charAt(i)]){
    
    
    obj[str.charAt(i)] = 1;
  }else{
    
    
    obj[str.charAt(i)]++
  }
}
var val= '';
var bigIndex  = '';
var bigStr = '';
var bigNum ='';

for(var index in obj){
    
    
  if(!bigIndex){
    
    
    bigIndex = index;
    bigNum = obj[index];
    
  }
  if(obj[index]>obj[bigIndex]){
    
    
    bigIndex = index;
    bigNum = obj[index];
  }
  
  bigStr = `${
      
      bigIndex}:${
      
      obj[bigIndex]}`;
  val += `${
      
      index}:${
      
      obj[index]}  `;
  
}

//遍历是否存在 出现同样次数的最多字符
for(var index in obj){
    
    
  if(bigNum == obj[index] &&index!=bigIndex){
    
    
    bigStr += `    ${
      
      index}:${
      
      obj[index]}`;
  }
}



document.getElementById('showStr').innerHTML = '字符串：'+str;
document.getElementById('showChar').innerHTML = '每个字符出现个数：' +val;
document.getElementById('bigStr').innerHTML =  '出现次数最多的字符：' +bigStr;