regex match a letter code example

Example 1: regex any letter

[a-zA-Z] //all letters
[a-z] //only lowercase letters
[A-Z] //only uppercase letters

Example 2: match regex

const regex = /([a-z]*)ball/g;
const str = "basketball football baseball";
let result;
while((result = regex.exec(str)) !== null) {
	console.log(result[1]); 
    // => basket
    // => foot
    // => base
}