Strings

String.prototype.includes(txt, start)

It was meant to be String.prototype.contains like the Array.prototype.contains but it would break MooTools

let title = 'JS Futures in London!';
title.includes('JS') // true
title.includes('!') // true
title.includes('JS', 3) // false

String.prototype.startsWith(txt, start)

title.startsWith('JS') // true
title.startsWith('js') // false
title.startsWith('F', 3) // true

String.prototype.endsWith(txt, start)

title.endsWith('!') // true
title.endsWith('London!') // true
title.endsWith('!', 3) // false
title.endsWith('Lon', 6) // true

String.prototype.repeat(count)

console.log('x'.repeat(3)) // 'xxx'
console.log('hello'.repeat(2)) // 'hellohello'

String.prototype.trim()

console.log(' x  '.trim()) // 'x'
console.log('  \tx'.trim()) // 'x'
console.log('foo bar\n'.trim()) // 'foo bar'

Template strings

Instead of using different quotes(single, double) we can use backticks(grave accent) to have properly interpolated expressions

var name = 'Marcin'
console.log(`Hello, name is ${ name }! \nThis sentence will be on the new line.`);
console.log(`Hello, name is ${ name }!
              This will be on the new line as well!`);

Tagged Template String

You can use functions to make adjustments to the strings. TODO: update with dedent example

qmmr/es6notes.md

Strings