use of substr() in js code example

Example 1: js get first 3 characters of string

const string = "0123456789";
console.log(string.slice(0, 2)); // "01"
console.log(string.slice(0, 8)); // "01234567"
console.log(string.slice(3, 7)); // "3456"

Example 2: javascript substring

// zero-based index, 'end' is excluded from result
myString.substring( start, end )