JavaScript每隔指定位数切割字符串

 
  
    function random(num) { 
   
  
        let byte_length = num || 32; 
   
  
        let chars = ''; 
   
  
        for (let i = 0; i < 26; i++) { 
   
  
            chars += String.fromCharCode(65 + i); 
   
  
        } 
   
  
 
  
        let lowerCase = chars.toLowerCase(); 
   
  
 
  
        let number = ''; 
   
  
        for (let i = 0; i < 10; i++) { 
   
  
            number += i; 
   
  
        } 
   
  
        let allChars = chars + lowerCase + number; 
   
  
 
  
        let result = ''; 
   
  
        for (let i = 0; i < byte_length; i++) { 
   
  
            result += allChars.charAt(parseInt(Math.random() * allChars.length)); 
   
  
        } 
   
  
        return result; 
   
  
    } 
   
  
 
  
    // 生成64位随机字符串 
   
  
    let data = random(64); 
   
  
    console.log(data); 
   
  
 
  
    function app(data, count) { 
   
  
        let arr = []; 
   
  
        for (let i = 0, len = data.length / count; i < len; i++) { 
   
  
            let subStr = data.substr(0, count); 
   
  
            arr.push(subStr); 
   
  
            data = data.replace(subStr, ''); 
   
  
        } 
   
  
 
  
        let newStr = arr.join('-'); 
   
  
        return newStr; 
   
  
    } 
   
  
 
  
    console.log(app(data, 4));