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useNumericLiterals

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Diagnostic Category: lint/style/useNumericLiterals

Since: v1.0.0

Sources:

Disallow parseInt() and Number.parseInt() in favor of binary, octal, and hexadecimal literals

JavaScript provides literal forms for binary, octal, and hexadecimal numbers. For example: 0b11, 0o77, and 0xff. Using the literal forms enable static code analysis and avoid unnecessary computations.

parseInt("111110111", 2);
code-block.js:1:1 lint/style/useNumericLiterals  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

This call to parseInt() can be replaced by a binary literal.

> 1 │ parseInt(“111110111”, 2);
^^^^^^^^^^^^^^^^^^^^^^^^
2 │

Using a literal avoids unnecessary computations.

Unsafe fix: Use the computed binary literal instead.

1 - parseInt(111110111,·2);
1+ 0b111110111;
2 2

Number.parseInt("767", 8);
code-block.js:1:1 lint/style/useNumericLiterals  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

This call to Number.parseInt() can be replaced by an octal literal.

> 1 │ Number.parseInt(“767”, 8);
^^^^^^^^^^^^^^^^^^^^^^^^^
2 │

Using a literal avoids unnecessary computations.

Unsafe fix: Use the computed octal literal instead.

1 - Number.parseInt(767,·8);
1+ 0o767;
2 2

Number.parseInt("-1f7", 16);
code-block.js:1:1 lint/style/useNumericLiterals  FIXABLE  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

This call to Number.parseInt() can be replaced by a hexadecimal literal.

> 1 │ Number.parseInt(“-1f7”, 16);
^^^^^^^^^^^^^^^^^^^^^^^^^^^
2 │

Using a literal avoids unnecessary computations.

Unsafe fix: Use the computed hexadecimal literal instead.

1 - Number.parseInt(-1f7,·16);
1+ -0x1f7;
2 2

parseInt(1);
parseInt(1, 3);
Number.parseInt(1);
Number.parseInt(1, 3);
0b111110111 === 503;
0o767 === 503;
0x1F7 === 503;
a[parseInt](1,2);
parseInt(foo);
parseInt(foo, 2);
Number.parseInt(foo);
Number.parseInt(foo, 2);