hollygood · May 17, 2021 01:54 · May 17, 2021 · May 4, 2021 · May 4, 2021 · Mar 2, 2021
diff --git a/some-tricks.md b/some-tricks.md
@@ -1,3 +1,5 @@
+# Some Common JS Tricks
+
 # Toggle Sorting function
 ```ts
 // Normal way
@@ -22,4 +24,93 @@ const compareBy = (prop, invert) => (a, b) => {
 };
 
 results = results[0].sort(compareBy(this.orderBy, this.order === 'desc'));
-```
+```
+# Sorting an array by multiple properties
+```ts
+export enum type {
+    high,
+    medium,
+    low
+}
+const array;
+array.sort((a, b) =>
+    type[a.type] - type[b.type] ||
+    a.desc - b.desc ||
+    a.time.localeCompare(b.time)
+);
+```
+
+# Compare two arrays of objects and remove the common objects or take common objects
+```ts
+const data = [{
+        id: "1",
+        name: "abc"
+    },
+    {
+        id: "2",
+        name: "cde"
+    },
+    {
+        id: "3",
+        name: "efg"
+    },
+    {
+        id: "4",
+        name: "hij"
+    },
+    {
+        id: "5",
+        name: "klm"
+    }
+];
+const data1 = [{
+        code: "23",
+        id: "1",
+        name: "abc"
+    },
+    {
+        code: "45",
+        id: "2",
+        name: "cde"
+    }
+];
+const result = data.filter(({
+    id
+}) => !data1.some(val => val.id === id));
+console.log(result);
+```
+# Get items from an array that equal to the values in an array?
+```ts
+let arr = [{'id': "1"}, {'id': "8"}]
+let ids =["1","2","3","4"];
+var findIndex = arr.filter(f => ids.indexOf(f.id)!=-1)
+// or
+var includes = arr.filter(f => ids.includes(f.id))
+```
+# Convert an array to an array of objects, selecting the key from another array
+```ts
+const propertyName = ['id', 'createid', 'sentid'];
+const value = [
+    ['1', '2', '3'],
+    ['3', '4', '5'],
+    ['6', '7', '8'],
+];
+const dataObjs = value.map(a =>
+    Object.fromEntries(a.map((e, i) => [propertyName[i], e]))
+);
+console.log(dataObjs);
+```
+# Merge two Arrays without duplicate items
+```ts
+// Lodash union
+_.union([1, 2, 3], [1, 2, 4 ,6])
+
+// Filter and concat 
+let a = [56, 43, 3], b = [11, 43, 56, 12]
+let c = a.concat(b)
+let d = c.filter((val, pos) => c.indexOf(val) === pos)
+
+// Set
+[...new Set([...array1 ,...array2])];
+```
+
diff --git a/some-tricks.md b/some-tricks.md
@@ -1,4 +1,4 @@
-# Remove repeat code 
+# Toggle Sorting function
 ```ts
 // Normal way
 if ( this.orderBy ) {

diff --git a/some-tricks.js → some-tricks.md b/some-tricks.js → some-tricks.md
@@ -1,4 +1,6 @@
-// Remove repeat code
+# Remove repeat code 
+```ts
+// Normal way
 if ( this.orderBy ) {
   results = this.order === 'asc' ? 
   results[0].sort( (a, b) => ( 
@@ -7,7 +9,7 @@ if ( this.orderBy ) {
     a[ this.orderBy ] < b[ this.orderBy ] ) ? 1 : -1 );
 }
 
-// New Approach
+// Better way
 const inversionFactor = this.order === 'asc' ? 1 : -1;
 results = results[0].sort( (a, b) =>
     a[ this.orderBy ] < b[ this.orderBy ] : -1 * inversionFactor : 1 * inversionFactor
@@ -19,4 +21,5 @@ const compareBy = (prop, invert) => (a, b) => {
     return (a[prop] < b[prop] ? -1 : 1) * (invert ? -1 : 1);
 };
 
-results = results[0].sort(compareBy(this.orderBy, this.order === 'desc'));
+results = results[0].sort(compareBy(this.orderBy, this.order === 'desc'));
+```
diff --git a/some-tricks.js b/some-tricks.js
@@ -0,0 +1,22 @@
+// Remove repeat code
+if ( this.orderBy ) {
+  results = this.order === 'asc' ? 
+  results[0].sort( (a, b) => ( 
+    a[ this.orderBy ] > b[ this.orderBy ] ) ? 1 : -1 ):
+  results[0].sort( (a, b) => ( 
+    a[ this.orderBy ] < b[ this.orderBy ] ) ? 1 : -1 );
+}
+
+// New Approach
+const inversionFactor = this.order === 'asc' ? 1 : -1;
+results = results[0].sort( (a, b) =>
+    a[ this.orderBy ] < b[ this.orderBy ] : -1 * inversionFactor : 1 * inversionFactor
+);
+
+// this is a reusable function and can go outside of other functions
+const compareBy = (prop, invert) => (a, b) => {
+    if (a[prop] === b[prop]) { return 0; } 
+    return (a[prop] < b[prop] ? -1 : 1) * (invert ? -1 : 1);
+};
+
+results = results[0].sort(compareBy(this.orderBy, this.order === 'desc'));
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