清除数组中的特定数值

 var ccc = [1,2,3,undefined,undefined,undefined,undefined,4,5,6]
  for(var i = 0;i<ccc.length;i++){
  if(typeof ccc[i] == "undefined"){
    ccc.splice(i,1)
  }
}

console.log(ccc)

var ccc = [1,2,3,undefined,undefined,undefined,undefined,4,5,6];
var ddd = [];
for(var i = 0;i<ccc.length;i++){
  if(typeof ccc[i] !== "undefined"){
    ddd.push(ccc[i])
  }
}

ccc = ddd;
console.log(ccc)

var ccc = [1,2,3,undefined,undefined,undefined,undefined,4,5,6]
alert(ccc.length)
for(var i = ccc.length;i>=0;i--){
  if(typeof ccc[i] == "undefined"){
    ccc.splice(i,1)
  }
}

console.log(ccc)

var ccc = [1,2,3,undefined,undefined,undefined,undefined,4,5,6];
ccc.toString().split(/,/)

console.log(ccc)