|
|
- var toInteger = require('./toInteger'),
- toNumber = require('./toNumber'),
- toString = require('./toString');
-
- /* Built-in method references for those with the same name as other `lodash` methods. */
- var nativeMin = Math.min;
-
- /**
- * Creates a function like `_.round`.
- *
- * @private
- * @param {string} methodName The name of the `Math` method to use when rounding.
- * @returns {Function} Returns the new round function.
- */
- function createRound(methodName) {
- var func = Math[methodName];
- return function(number, precision) {
- number = toNumber(number);
- precision = precision == null ? 0 : nativeMin(toInteger(precision), 292);
- if (precision) {
- // Shift with exponential notation to avoid floating-point issues.
- // See [MDN](https://mdn.io/round#Examples) for more details.
- var pair = (toString(number) + 'e').split('e'),
- value = func(pair[0] + 'e' + (+pair[1] + precision));
-
- pair = (toString(value) + 'e').split('e');
- return +(pair[0] + 'e' + (+pair[1] - precision));
- }
- return func(number);
- };
- }
-
- module.exports = createRound;
|