Javascript Math random可在不复制的情况下在数组中查找名称
所以我想从一个名称数组中找出三个名称,然后我想把它们写到一个新的数组中,虽然还没有到现在为止,但是我的问题是,它一直在随机化我已经找到的相同的名称 看看这本书 代码:Javascript Math random可在不复制的情况下在数组中查找名称,javascript,arrays,math,random,Javascript,Arrays,Math,Random,所以我想从一个名称数组中找出三个名称,然后我想把它们写到一个新的数组中,虽然还没有到现在为止,但是我的问题是,它一直在随机化我已经找到的相同的名称 看看这本书 代码: findStudentBtn.onclick = findStudent; function findStudent() { var studArray = ["John","Daniel","Hans","Lars","Tom","Amanda","Jane","Sarah"] //1-8 for (i=0;
findStudentBtn.onclick = findStudent;
function findStudent() {
var studArray = ["John","Daniel","Hans","Lars","Tom","Amanda","Jane","Sarah"] //1-8
for (i=0; i<3; i++) {
if (i=1) {
var randomStud1 = studArray[Math.floor(studArray.length * Math.random())];
msg8.innerHTML += randomStud1 + ", ";
}
if (i=2) {
var randomStud2 = studArray[Math.floor(studArray.length * Math.random())];
msg8.innerHTML += randomStud2 + ", ";
}
if (i=3) {
var randomStud3 = studArray[Math.floor(studArray.length * Math.random())];
msg8.innerHTML += randomStud3 + ", ";
}
if (randomStud1 == randomStud2 || randomStud2 == randomStud3 || randomStud1 == randomStud3){
ms8.innerHTML = "";
findStudent();
}
}
}
对于任何对解决方案感兴趣但不愿意使用jsfidle的人,下面是我使用的脚本
findStudentBtn.onclick = function(){
findStudent();
};
var r_stud = ["John","Daniel","Hans","Lars","Tom","Amanda","Jane","Sarah"];
var r_rndm = [];
var r_newr = [];
function getStudent(){
//if the amount of available people, is to small to reach 3.
if(r_rndm.length == r_stud.length){
//reset the random selected array
r_rndm = [];
return r_newr;
}
//select a student
var i_randomStudent = Math.floor(r_stud.length * Math.random());
var s_randomStudent = r_stud[i_randomStudent];
if(r_rndm.indexOf(s_randomStudent) >= 0){
//if it's allready been selected, try again.
getStudent();
}else{
//add students to new selection and to alltime selection
r_rndm.push(s_randomStudent);
r_newr.push(s_randomStudent);
//return the new array
return r_newr;
}
};
function findStudent(){
//reset new array.
r_newr = [];
for(i = 0; i < 3; i++){
getStudent();
};
//print contents of new array to console.
console.log(r_newr);
for(i = 0; i < r_newr.length; i++){
separator = (i == r_newr.length - 1 && r_rndm.length == 0 ) ? '' : ', ';
msg8.innerHTML += r_newr[i] + separator;
}
};
谷歌如何在Javascript中设置随机数生成器种子-我不记得了,但如果每次运行都得到相同的序列,那就是问题所在。一种不重复随机选择的流行方法是随机洗牌数组,然后取前N个元素。如果I=1{与其说是一个条件,不如说是一个赋值。如果i==1,您希望{一种可能是始终跟踪您已经选择的索引,然后获得另一个随机数,如果它与您已经选择的任何索引相同。它不是很优雅,但很有效。我已经更新了jsfidle,这给了您想要的效果。非常感谢您的回答。这基本上是我想要的,但我有一个问题:r_rndm.indexOfs_randomstudio>=0行到底做了什么?为什么大于或等于0?indexOf给出了要检查的变量的第一个实例的索引,在本例中,我们在数组r_rndm中查找新名称s_randomstudior的第一个索引。如果它在数组中,它将返回0或其他值g Biger,如果不是,它将返回-1。非常感谢!你帮了我很大的忙