JavaScript .filter 和 .find 有问题以返回带有特定字母的项目

Question

在以下 JavaScript 代码中，我试图获取包含字母“Y”或“y”的名称。 当我查找如何做到这一点时，我看到了.filter和.find方法。 但是这段代码只返回containsY = ['Tommy'] 。 我试过for loop ，但.find只返回提供条件中第一个元素的值，它不会返回所有带有“y”的名称。 有没有更好的方法来获取所有“Y”和“y”名称？

const students = ["Tommy","Noah","Xander","Adil","Bradley","Nicholas","Damien"]

      let containsY = students.filter((student) => student.includes("Y"))

      //Look for name with "y", and push it to containsY
      containsY.push(students.find((student) => student.includes("y")))

      console.log(containsY)

Answer 1

你的filter方法很好。 它给出了不正确的结果，因为includes区分大小写。

相反，在filter回调中，将student转换为小写，然后检查它是否包含"y" ：

 const students = ["Tommy","Noah","Xander","Adil","Bradley","Nicholas","Damien"] const res = students.filter((student) => student.toLowerCase().includes("y")) console.log(res)

Answer 2

要么使用正则表达式（它的好处是只需要一个测试）

 const students = ["Tommy", "Noah", "Xander", "Adil", "Bradley", "Nicholas", "Damien"] const result = students.filter(student => /y/i.test(student)) console.log(result)

或者在（单个）回调中测试.includes('y')和.includes('Y') 。

 const students = ["Tommy", "Noah", "Xander", "Adil", "Bradley", "Nicholas", "Damien"] const result = students.filter(student => student.includes('y') || student.includes('Y')); console.log(result)