Math.max()
Math.max()
函式會回傳零或多個數字中的最大值。
嘗試一下
語法
Math.max([value1[, value2[, ...]]])
Parameters
value1, value2, ...
-
Numbers.
Return value
The largest of the given numbers. If at least one of the arguments cannot be converted to a number, NaN
is returned.
說明
範例
Using Math.max()
Math.max(10, 20); // 20
Math.max(-10, -20); // -10
Math.max(-10, 20); // 20
Getting the maximum element of an array
Array.reduce()
can be used to find the maximum element in a numeric array, by comparing each value:
var arr = [1,2,3];
var max = arr.reduce(function(a, b) {
return Math.max(a, b);
}, -Infinity);
The following function uses Function.prototype.apply()
to get the maximum of an array. getMaxOfArray([1, 2, 3])
is equivalent to Math.max(1, 2, 3)
, but you can use getMaxOfArray()
on programmatically constructed arrays. This should only be used for arrays with relatively few elements.
function getMaxOfArray(numArray) {
return Math.max.apply(null, numArray);
}
The new spread operator (en-US) is a shorter way of writing the apply
solution to get the maximum of an array:
var arr = [1, 2, 3];
var max = Math.max(...arr);
However, both spread (...
) and apply
will either fail or return the wrong result if the array has too many elements, because they try to pass the array elements as function parameters. See Using apply
and built-in functions for more details. The reduce
solution does not have this problem.
規範
Specification |
---|
ECMAScript Language Specification # sec-math.max |
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