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SyntaxError: "0"-prefixed octal literals and octal escape seq. are deprecated - JavaScript | MDN
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SyntaxError: "0"-prefixed octal literals and octal escape seq. are deprecated

    SyntaxError: Octal numeric literals and escape characters not allowed in strict mode (Edge)
    SyntaxError:
    "0"-prefixed octal literals and octal escape sequences are deprecated;
    for octal literals use the "0o" prefix instead

In this article

SyntaxError strict mode .

?

8 8 , (strict mode) SyntaxError . ECMAScript 2015 0 "O" . (0o 0O)

"0" 8

js
"use strict";

03;

// SyntaxError: "0"-prefixed octal literals and octal escape sequences
// are deprecated (0  8 8      . )

8

js
"use strict";

"\251";

// SyntaxError: "0"-prefixed octal literals and octal escape sequences
// are deprecated (0  8 8      . )

8

0 "o" "O" . :

js
0o3;

8 16 . :

js
"\xA9";

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