JS数组求和的常用方法。一、for循环vararr=[1,2,3];
functionsum(arr){
vars=0;
for(vari=0;iarr.length;i++){
s+=arr[i];
}
returns;
}
console.log(sum(arr));//6二、forEach遍历vararr=[1,2,3];
functionsum(arr){
vars=0;
arr.forEach(function(val,idx,arr){
s+=val;
},0);
returns;
};
console.log(sum(arr));//6三、reducevararr=[1,2,3];
functionsum(arr){
returnarr.reduce(function(acr,cur){
returnacr+cur;
});
}
console.log(sum(arr));//6四、递归vararr=[1,2,3];
functionsum(arr){
if(arr.lengt