为什么我的for循环中的if语句不能在Java脚本中运行

我正在运行此程序，它会根据一些提示性问题，从旧的对象数组中生成一个新的数组。但是，当我运行程序时，循环中if无法识别该语句for。新数组包含新数组中的所有内容。

function verb(first,second,third,fourth,conjugation,chapter) {

    this.first = first;
    this.second = second;
    this.third = third;
    this.fourth = fourth;
    this.conjugation = conjugation;
    this.chapter = chapter;
}
// Now we can make an array of people
/*var family = new Array();
family[0] = new Person("alice", 40);
family[1] = new Person("bob", 42);
family[2] = new Person("michelle", 8);
// add the last family member, "timmy", who is 6 years old
family[3] = new Person("timmy", 6);*/

var family = new Array();

family[0] = new verb("amo","amare","amavi",'amatum',1,1);
family[1] = new verb("moneo","monere","monui","monitum",2,1);
family[2] = new verb("a  "," a"," a","a ",3,6);
family[3] = new verb("debeo","debere","debui","debitum",2,1);
family[4] = new verb("do","dare","dedi","datum",1,1);
family[5] = new verb("servo","servare","servavi","servatum",1,1);
family[6] = new verb("conservo","conservare","conservavi","conservatum",1,1);
family[7] = new verb("terreo","terrere","terrui","territum",1,1);
family[8] = new verb("valeo","valere","valui","valitum",2,1);
family[9] = new verb("video","videre","vid","visum",2,1);
family[10] = new verb("voco","vocare","vocavi","vocatum",1,1);
family[11] = new verb("habeo","habere","habui","habitum",2,3);
family[12] = new verb("satio","satiare","satiavi","satiatum",1,3);
family[13] = new verb("culp","culpare","culpavi","culpatum",1,5);
family[14] = new verb(" ceno","cenare","cenavi","cenatum",1,5);
family[15] = new verb("maneo","manere","mansi","mansum",2,5);
family[16] = new verb("supero","supweare","superavi","superatum",1,5);
family[17] = new verb("tolero","tolerare","toleravi","toleratum",1,6);
family[18] = new verb("audeo","audere","ausus sum","   ",2,7);
family[19] = new verb("neco","necare","necavi","necatum",1,7);
family[20] = new verb("ago","agere","egi","actum",3,8);

var choose = prompt("do you want principle parts ?");
/*<?php echo $_POST["name"]; ?>




/*family[1] = new verb
family[2] = new verb

family[0].chapter
/*"var doceo = {
    definition:"to teach",
    first:"doceo",
    second:"docere",
    third:"dixi",
    fourth:"doctum"
    chapter:"3""*/

/*chap_beg = document.getElementById("0").submit;
chap_end = document.getElementByID("1").submit;*/

var chap_beg =   prompt("What chapter do you want to begin?");
/*var chap_beg = <?php echo $_POST["name"]; ?>*/
var chap_end = prompt("what chapter do you want too end"); 
/* var chap_end = <?php echo $_POST["name"]; ?>*/
/*if((Math.random())*6<1){
    person = 1;
}else if(1<(Math.random())*6<2){
    person = 2;
}else if(2<(Math.random())*6<3){
    person = 3;
}else if(3<(Math.random())*6<4){
  person = 4;
}else if(4<(Math.random())*6<5){
 person = 5;
}else if(5<(Math.random())*6<5){
    person = 6;
} */


var helparray = new Array();
helparray[1]=1;
helparray[2]=2;
helparray[3]=3;
helparray[4]=4;
helparray[5]=5;
helparray[6]=6;

 var person = helparray[Math.floor(Math.random() * helparray.length)];   



var randselect  = new Array();


for(i=0;i<family.length;i++) {


if( chap_beg < family[i].chapter <  chap_end) {

    console.log(family[i].first);
     randselect.push(family[i]);

  }else{
      console.log("no");
  }

    /* console.log(randselect[randselect.length-1]);*/


}
     var rand = randselect[Math.floor(Math.random() * (randselect.length - 1))];
     /*var rand = randselect[Math.round(Math.random() * (randselect.length - 1))];*/`enter code here`

屈服

amo
moneo
a  
debeo
do
servo
conservo
terreo
valeo
video
voco
habeo
satio
culp
 ceno
maneo
supero
tolero
audeo
neco
ago