Js基础教程之if和switch

var a=6;
if(){
  
}else if(){
  
}else{
  
}


if(a>9){
  console.log("大于9");
}else if(a>6){
  console.log("大于6");
}else if(a>6){
  console.log("大于6");
}else{
  console.log("小于9");
}
if(a>9){
  console.log("大于9");
}else{
  
}

switch(a){
  case 1:
    console.log("a=1");
    break;
  case 7:
    console.log("a=7");
    break;
  default:
    console.log("a不等于1或者7");
    break;
    
}