js定义数组arr=[12,54,23,67,90,2,3,7,9,10,11,45]，所有数组元素和
1、reduce
[12,54,23,67,90,2,3,7,9,10,11,45].reduce((a, b) => a + b)
2、eval
eval([12,54,23,67,90,2,3,7,9,10,11,45].join('+'))
3、forEach
function sum(arr) {
var result = 0;
arr.forEach((v) => {
result += v;
}, 0);
return result;
};
let arr = [12, 54, 23, 67, 90, 2, 3, 7, 9, 10, 11, 45]
let eveal=eval(arr.join("+"))
let arr=[12,54,23,67,90,2,3,7,9,10,11,45]
function sum() {
return eval(arr.join("+"));
}
console.log(sum())
使用reduce即可
<script>
function sumArr(arr) {
return arr.reduce(function (total, value) {
return total + value;
}, 0);
}
var arr = [1, 2, 3, 4];
console.log(sumArr(arr)); // 10
</script>
function sum(arr) {
var s = 0;
for (var i=arr.length-1; i>=0; i--) {
s += arr[i];
}
return s;
}
var arr=[12,54,23,67,90,2,3,7,9,10,11,45];
document.write(sum(arr));
const arr = [12, 54, 23, 67, 90, 2, 3, 7, 9, 10, 11, 45];
const sum = arr.reduce((acc, cur) => acc + cur, 0);
console.log(sum); // 输出结果为：333