'x'.padStart(5,ab') // 'ababx'
4,1)"> 'abax'
'.padEnd( 'xabab'
'xaba'
**********************
hello'.repeat(2) "hellohello"
na0) ""
**********************
var s = Hello world!';
s.startsWith(Hello true
s.endsWith(! true
s.includes(o true
**********************
String.fromCodePoint(0x78,1)">0x1f680,1)">0x79) === x\uD83D\uDE80y'
true
"
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