Checking the characters of a string in JavaScript

Let some string consisting of digits be given:

let str = '12345';

Let's check if the first character of this string is equal to the number 1:

let str = '12345'; if (str[0] == 1) { console.log('!'); }

Let's now check the last character for equality to the number 5:

let str = '12345'; let last = str[str.length - 1]; if (last == 5) { console.log('!'); }

Given a variable containing some string. Check that this string starts with character 'a'.

Given a variable containing some string. Check that this string ends with the character 'x'.

Given a variable containing some string. Check that this string starts with the character 'a' or the character 'b'.

enru