Easy JavaScript solution
Intuition\n Describe your first thoughts on how to solve this problem. \n\n# Approach\n Describe your approach to solving the problem. \n\n# Complexity\n- Time 
# Intuition\n<!-- Describe your first thoughts on how to solve this problem. -->\n\n# Approach\n<!-- Describe your approach to solving the problem. -->\n\n# Complexity\n- Time complexity:\n<!-- Add your time complexity here, e.g. $$O(n)$$ -->\n\n- Space complexity:\n<!-- Add your space complexity here, e.g. $$O(n)$$ -->\n\n# Code\n```javascript []\n/**\n * @param {number[]} nums\n * @param {number} target\n * @return {number}\n */\nvar countPairs = function(nums, target) {\n    let count=0\n    for(let i=0;i<nums.length;i++){\n        for(let j=i+1;j<nums.length;j++){\n            if(nums[i]+nums[j]<target){\n                count++;\n            }\n        }\n    }return count\n};\n```
['Array', 'Two Pointers', 'Binary Search', 'Sorting', 'JavaScript']