RangeError: precision is out of range - JavaScript 编辑

The JavaScript exception "precision is out of range" occurs when a number that's outside of the range of 0 and 20 (or 21) was passed into toFixed or toPrecision.

Message

RangeError: The number of fractional digits is out of range (Edge)
RangeError: The precision is out of range (Edge)
RangeError: precision {0} out of range (Firefox)
RangeError: toExponential() argument must be between 0 and 20 (Chrome)
RangeError: toFixed() digits argument must be between 0 and 20 (Chrome)
RangeError: toPrecision() argument must be between 1 and 21 (Chrome)

Error type

RangeError

What went wrong?

There was an out of range precision argument in one of these methods:

• Number.prototype.toExponential()
• Number.prototype.toFixed()
• Number.prototype.toPrecision()

The allowed range for these methods is usually between 0 and 20 (or 21). However, the ECMAScript specification allows to extend this range.

Examples

Invalid cases

77.1234.toExponential(-1);  // RangeError
77.1234.toExponential(101); // RangeError

2.34.toFixed(-100);         // RangeError
2.34.toFixed(1001);         // RangeError

1234.5.toPrecision(-1);     // RangeError
1234.5.toPrecision(101);    // RangeError

Valid cases

77.1234.toExponential(4); // 7.7123e+1
77.1234.toExponential(2); // 7.71e+1

2.34.toFixed(1); // 2.3
2.35.toFixed(1); // 2.4 (note that it rounds up in this case)

5.123456.toPrecision(5); // 5.1235
5.123456.toPrecision(2); // 5.1
5.123456.toPrecision(1); // 5

See also

• Number.prototype.toExponential()
• Number.prototype.toFixed()
• Number.prototype.toPrecision()