copy of substring js code example
Example 1: js substring
// the substring method returns a string out of another string
const str = 'Mozilla';
console.log(str.substring(1, 3));
// expected output: "oz"
console.log(str.substring(2));
// expected output: "zilla"
Example 2: js substr
//str.substr(start[, length])
var str = 'abcdefghij';
console.log('(1, 2): ' + str.substr(1, 2)); // '(1, 2): bc'
console.log('(-3, 2): ' + str.substr(-3, 2)); // '(-3, 2): hi'
console.log('(-3): ' + str.substr(-3)); // '(-3): hij'
console.log('(1): ' + str.substr(1)); // '(1): bcdefghij'
console.log('(-20, 2): ' + str.substr(-20, 2)); // '(-20, 2): ab'
console.log('(20, 2): ' + str.substr(20, 2)); // '(20, 2): '