为什么 while 循环会忽略它的 != 规则

Question

所以基本上这是我在学校遇到的关于怪物和你的能量的问题，从第一个索引开始，之后的每个是与怪物战斗需要多少能量才能杀死它。如果您赢得了 3 场战斗，您的能量点将获得战斗计数。所以我注意到 End of Battle 字符串通过了 while 循环，即使我将它置于 != :/

的条件中

对不起，我有点菜鸟..

function dude(input) {
    // inital energy as input(shift)
    let energy = Number(input.shift());
    // we create a count and ++ it for every itteration
    let count = 0;
    // while input[0] is NOT "End Of Battle" and energy > 0
    while (input[0] !== 'End Of Battle' && energy > 0) {
        
        // input.shift() is how much energy we will need for each monster
        let monster = Number(input.shift());
        
        // we substract that input[0].shift() energy from the starting energy
        energy -= monster
        count++;
        if (count % 3 === 0) {
            energy += count;
        }
console.log(energy);
}
if(energy <= 0){
    console.log(`Not enough energy! Game ends with ${count} won battles and ${energy} energy`);
 }else{
     console.log(`Won battles: ${count}. Energy left: ${Number(energy)}`);
 }
}
dude((["200",
"54",
"14",
"28",
"13",
"End of battle"]));

Answer 1

您正在发送字符串 'End of battle' 并将其与 'End Of Battle' 进行比较。他们不一样。为了保护自己免受此类差异的影响，您可以在比较之前规范化字符串（trim 去掉任何多余的白色 space 并转换为小写）。我调整了这一行，现在可以使用了：

if (input[0].trim().toLowerCase() !== 'end of battle' && ...)

function dude(input) {
  // inital energy as input(shift)
  let energy = Number(input.shift());
  // we create a count and ++ it for every itteration
  let count = 0;
  // while input[0] is NOT "End Of Battle" and energy > 0
  while (input[0].trim().toLowerCase() !== 'end of battle' && energy > 0) {
    // input.shift() is how much energy we will need for each monster
    let monster = Number(input.shift());

    // we substract that input[0].shift() energy from the starting energy
    energy -= monster
    count++;
    if (count % 3 === 0) {
      energy += count;
    }
    console.log('energy', energy);
  }
  if (energy <= 0) {
    console.log(`Not enough energy! Game ends with ${count} won battles and ${energy} energy`);
  } else {
    console.log(`Won battles: ${count}. Energy left: ${Number(energy)}`);
  }
}
dude(["200",
  "54",
  "14",
  "28",
  "13",
  "End of battle"
]);

为什么 while 循环会忽略它的 != 规则

why does that while loop ignore it's != rule

javascript

loops

while-loop

conditional-statements