Adding solution for issue 124

solutions/124.js

@@ -0,0 +1,38 @@
+// Natalie Lockhart
+// Find the first non-duplicate value in an array
+
+const solution = (arr) => {
+
+  if (arr.length == 0) {
+    return null;
+  }
+
+  if (arr.length == 1){
+    return arr[0];
+  }
+
+  function checkDuplicates(testArr, compareNum){
+    for (a = 0; a < testArr.length; a++){
+      if(compareNum == testArr[a]){
+        return null;
+	  }
+	  else if(a == testArr.length-1){
+        return compareNum;	
+	  }
+    }
+  }  
+
+  for (i = 0; i < arr.length; i++){
+	var testArr = arr.slice();
+	testArr.splice(i,1);
+    var result = checkDuplicates(testArr, arr[i]);
+	if(result != null){
+		return result;
+	}
+  }
+  return null;
+}
+
+module.exports = {
+  solution,
+};

test/124.js

@@ -0,0 +1,25 @@
+const expect = require('chai').expect;
+let solution = require('../solutions/124').solution;
+
+describe('first non-duplicate number in an array', () => {
+  it('should return null for []', () => {
+    const result = solution([]);
+	expect(result).to.equal(null);
+  });
+  it('should return 1 for [1]', () => {
+    const result = solution([1]);
+	expect(result).to.equal(1);
+  });
+  it('should return null for [1,1,2,2,3,3]', () => {
+    const result = solution([1,1,2,2,3,3]);
+	expect(result).to.equal(null);
+  });
+  it('should return 2 for [1,1,2,3,3,4,4,5,5]', () => {
+    const result = solution([1,1,2,3,3,4,4,5,5]);
+	expect(result).to.equal(2);
+  });
+  it('should return 2 for [1,1,2,3]', () => {
+    const result = solution([1,1,2,3]);
+	expect(result).to.equal(2);
+  });
+});