数字转换为二进制

function get2bin(num){
    
    var bin = "";
    while (num > 0) {
        
        if (num%2 != 0) { 
            bin = "1" + bin; 
        } else { 
            bin = "0" + bin; 
        }
        num = parseInt(num/2);

    }
    return bin;

}