前哨程序不起作用

Question

我是初學者，我需要一些幫助來完成我的任務。我無法弄清楚我做錯了什麼。

我必須製作一個程序來讀取一系列值爲0到100和-1的考試分數以停止處理。輸入並驗證分數。程序應計算並打印通過次數（> = 50）和失敗次數（0-50）。當輸入-1分時，顯示通過次數和失敗次數。

<script> 
var score = 0; 
var passCount = 0; 
var failCount = 0; 

score = parseInt(prompt("Input score between 1-100, -1 to quit","0")); 

while (score !< 0){ 
    if (score >= 50 || score <= 100){ 
    passCount = passCount + 1; 
    alert ("You passed! Pass count = "+passCount+"Fail count = "+failCount); 
    } 
    else 
    if (score<50){ 
    failCount = failCount + 1; 
    alert ("You failed! Pass count = "+passCount+"Fail count = "+failCount); 
    } 
    else 
    if (score > 100){ 
    alert ("Invalid number"); 
    } 
    score = parseInt(prompt("Input score between 1-100, -1 to quit","0")); 
} 
document.write ("Total: Passes - "+passCount+"Fails "+failCount); 
</script> 

Answer 1

變更，必須做到：

1. while (score >= 0)

   沒有運營商!<。你要麼必須使用while (! (score<0))或while (score >=0)或while (score != -1)

2. 如果（得分> = 50 &&得分< = 100）

   既然你是在原來代碼中使用||OR操作，控制永不熄滅故障計數分支。需要使用AND運算符才能使條件生效。

最終代碼：

<script> 
var score = 0; 
var passCount = 0; 
var failCount = 0; 

score = parseInt(prompt("Input score between 1-100, -1 to quit","0")); 

while (score >= 0){ 
    if (score >= 50 && score <= 100){ 
    passCount = passCount + 1; 
    alert ("You passed! Pass count = "+passCount+"Fail count = "+failCount); 
    } 
    else 
    if (score<50){ 
    failCount = failCount + 1; 
    alert ("You failed! Pass count = "+passCount+"Fail count = "+failCount); 
    } 
    else 
    if (score > 100){ 
    alert ("Invalid number"); 
    } 
    score = parseInt(prompt("Input score between 1-100, -1 to quit","0")); 
} 
document.write ("Total: Passes - "+passCount+"Fails "+failCount); 
</script> 

Answer 2

嘗試改變你的病情while(score != -1)