数组求和-JS

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function

sum(arr) {

var

len = arr.length;

if

(len == 0){

return

0;

}

else

if

(len == 1){

return

arr[0];

}

else

{

return

arr[0] + sum(arr.slice(1));

}

}

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function

sum(arr) {

var

s = 0;

for

(

var

i=arr.length-1; i>=0; i--) {

s += arr[i];

}

return

s;

}

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function

sum(arr) {

return

arr.reduce(

function

(prev, curr, idx, arr){

return

prev + curr;

});

}

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function

sum(arr) {

var

s = 0;

arr.forEach(

function

(val, idx, arr) {

s += val;

}, 0);

return

s;

};

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function

sum(arr) {

return

eval(arr.join(

"+"

));

};