在javascript中使用箭头函数返回名字和姓氏的首字母

Question

Trying to have console log show the initials of the first and last name when using arrow functions in javascript.

 const getInitials = (firstName, lastName) => { firstName + lastName; } console.log(getInitials("Charlie", "Brown"));

Answer 1

You have to specify return inside the curly brackets. You can use charAt() to get the initials:

 const getInitials = (firstName,lastName) => { return firstName.charAt(0) + lastName.charAt(0); } console.log(getInitials("Charlie", "Brown"));

OR: You do not need the return if remove the curly brackets:

 const getInitials = (firstName,lastName) => firstName.charAt(0) + lastName.charAt(0); console.log(getInitials("Charlie", "Brown"));

Answer 2

You're not returning the initials, you're returning the whole name. Use [0] to get the first character of a string.

In an arrow function, don't put the expression in {} if you just want to return it as a result.

 const getInitials = (firstName, lastName) => firstName[0] + lastName[0]; console.log(getInitials("Charlie", "Brown"));

Answer 3

Get first chars from names.

 const getInitials = (firstName, lastName) => `${firstName[0]}${lastName[0]}` console.log(getInitials("Charlie", "Brown"));

Answer 4

When you give an arrow function a code block ( {} ), you need to explicitly define the return statement. In your example, you don't need a code block since you're only wanting to return a single value. So, you can remove the code block, and instead place the return value to the right of the arrow => .

In order to get the first characters in your strings, you can use bracket notation ( [0] ) to index the string, .charAt(0) , or even destructuring like so:

 const getInitials = ([f],[s]) => f + s; console.log(getInitials("Charlie", "Brown"));

Answer 5

const getInitials = (firstName,lastName) => { return firstName.charAt(0) + lastName.charAt(0); }
console.log(getInitials("Charlie", "Brown"));