检查第一个单词是否是大写的，解决方案是否为false

Question

在[0]之前的

肯定是大写的，所以我很困惑为什么它会评估为假

function myReplace(str, before, after) {
    console.log(before[0] === before[0].toUpperCase();
}

myReplace("A quick brown fox jumped over the lazy dog", "Jumped", "leaped");

Answer 1

你指的是toUpperCase函数。你需要调用它才能获得值

＆＃13;

＆＃13;

function myReplace(str, before, after) {
    console.log(before[0] === before[0].toUpperCase());
}

myReplace("A quick brown fox jumped over the lazy dog", "Jumped", "leaped");

＆＃13;

＆＃13;

＆＃13;

Answer 2

这次你忘了关闭console.log，它应该是：

  function myReplace(str, before, after) {
    console.log(before[0] === before[0].toUpperCase());
}

myReplace("A quick brown fox jumped over the lazy dog", "Jumped", "leaped");

Answer 3

天啊，你应该添加括号：

function myReplace(str, before, after) {
    console.log(before[0] === before[0].toUpperCase());
}

myReplace("A quick brown fox jumped over the lazy dog", "Jumped", "leaped");