From fc3d013aeba31793dea0ea3dcf45b1584bfb07d8 Mon Sep 17 00:00:00 2001 From: Michael Wilson Date: Wed, 2 Oct 2024 16:19:42 -0700 Subject: [PATCH] Use let instead of var in examples --- explainer.md | 50 +++++++++++++++++++++++++------------------------- index.html | 12 ++++++------ 2 files changed, 31 insertions(+), 31 deletions(-) diff --git a/explainer.md b/explainer.md index 3b98d8d..48abf97 100644 --- a/explainer.md +++ b/explainer.md @@ -7,7 +7,7 @@ The following are some examples of common MIDI usage in JavaScript. This example shows how to request access to the MIDI system. ```js -var midi = null; // global MIDIAccess object +let midi = null; // global MIDIAccess object function onMIDISuccess( midiAccess ) { console.log( "MIDI ready!" ); @@ -26,7 +26,7 @@ This example shows how to request access to the MIDI system, including the ability to send and receive System Exclusive messages. ```js -var midi = null; // global MIDIAccess object +let midi = null; // global MIDIAccess object function onMIDISuccess( midiAccess ) { console.log( "MIDI ready!" ); @@ -46,15 +46,15 @@ information to the console log, using ES6 for...of notation. ```js function listInputsAndOutputs( midiAccess ) { - for (var entry of midiAccess.inputs) { - var input = entry[1]; + for (let entry of midiAccess.inputs) { + let input = entry[1]; console.log( "Input port [type:'" + input.type + "'] id:'" + input.id + "' manufacturer:'" + input.manufacturer + "' name:'" + input.name + "' version:'" + input.version + "'" ); } - for (var entry of midiAccess.outputs) { - var output = entry[1]; + for (let entry of midiAccess.outputs) { + let output = entry[1]; console.log( "Output port [type:'" + output.type + "'] id:'" + output.id + "' manufacturer:'" + output.manufacturer + "' name:'" + output.name + "' version:'" + output.version + "'" ); @@ -68,8 +68,8 @@ the console log. ```js function onMIDIMessage( event ) { - var str = "MIDI message received at timestamp " + event.timeStamp + "[" + event.data.length + " bytes]: "; - for (var i=0; i<event.data.length; i++) { + let str = "MIDI message received at timestamp " + event.timeStamp + "[" + event.data.length + " bytes]: "; + for (let i=0; i<event.data.length; i++) { str += "0x" + event.data[i].toString(16) + " "; } console.log( str ); @@ -87,8 +87,8 @@ queues a corresponding note off message for 1 second later. ```js function sendMiddleC( midiAccess, portID ) { - var noteOnMessage = [0x90, 60, 0x7f]; // note on, middle C, full velocity - var output = midiAccess.outputs.get(portID); + let noteOnMessage = [0x90, 60, 0x7f]; // note on, middle C, full velocity + let output = midiAccess.outputs.get(portID); output.send( noteOnMessage ); //omitting the timestamp means send immediately. output.send( [0x80, 60, 0x40], window.performance.now() + 1000.0 ); // Inlined array creation- note off, middle C, // release velocity = 64, timestamp = now + 1000ms. @@ -100,8 +100,8 @@ This example loops all input messages on the first input port to the first output port - including System Exclusive messages. ```js -var midi = null; // global MIDIAccess object -var output = null; +let midi = null; // global MIDIAccess object +let output = null; function echoMIDIMessage( event ) { if (output) { @@ -111,7 +111,7 @@ function echoMIDIMessage( event ) { function onMIDISuccess( midiAccess ) { console.log( "MIDI ready!" ); - var input = midiAccess.inputs.entries().next(); + let input = midiAccess.inputs.entries().next(); if (input) input.onmidimessage = echoMIDIMessage; output = midiAccess.outputs.values().next().value; @@ -135,14 +135,14 @@ are not. This sample is also hosted on webaudiodemos.appspot.com. ```js -var context=null; // the Web Audio "context" object -var midiAccess=null; // the MIDIAccess object. -var oscillator=null; // the single oscillator -var envelope=null; // the envelope for the single oscillator -var attack=0.05; // attack speed -var release=0.05; // release speed -var portamento=0.05; // portamento/glide speed -var activeNotes = []; // the stack of actively-pressed keys +let context=null; // the Web Audio "context" object +let midiAccess=null; // the MIDIAccess object. +let oscillator=null; // the single oscillator +let envelope=null; // the envelope for the single oscillator +let attack=0.05; // attack speed +let release=0.05; // release speed +let portamento=0.05; // portamento/glide speed +let activeNotes = []; // the stack of actively-pressed keys window.addEventListener('load', function() { // patch up prefixes @@ -167,9 +167,9 @@ window.addEventListener('load', function() { function onMIDIInit(midi) { midiAccess = midi; - var haveAtLeastOneDevice=false; - var inputs=midiAccess.inputs.values(); - for ( var input = inputs.next(); input && !input.done; input = inputs.next()) { + let haveAtLeastOneDevice=false; + let inputs=midiAccess.inputs.values(); + for ( let input = inputs.next(); input && !input.done; input = inputs.next()) { input.value.onmidimessage = MIDIMessageEventHandler; haveAtLeastOneDevice = true; } @@ -209,7 +209,7 @@ function noteOn(noteNumber) { } function noteOff(noteNumber) { - var position = activeNotes.indexOf(noteNumber); + let position = activeNotes.indexOf(noteNumber); if (position!=-1) { activeNotes.splice(position,1); } diff --git a/index.html b/index.html index 8013374..88b9f64 100644 --- a/index.html +++ b/index.html @@ -455,18 +455,18 @@

ports. This enables: 

    // to tell how many entries there are:
-    var numberOfMIDIInputs = inputs.size;
+    let numberOfMIDIInputs = inputs.size;
 
     // add each of the ports to a <select> box
     inputs.forEach( function( port, key ) {
-      var opt = document.createElement("option");
+      let opt = document.createElement("option");
       opt.text = port.name;
       document.getElementById("inputportselector").add(opt);
     });
 
     // or you could express in ECMAScript 6 as:
     for (let input of inputs.values()) {
-      var opt = document.createElement("option");
+      let opt = document.createElement("option");
       opt.text = input.name;
       document.getElementById("inputportselector").add(opt);
     }
@@ -489,18 +489,18 @@

output ports=]. This enables: 

    // to tell how many entries there are:
-    var numberOfMIDIOutputs = outputs.size;
+    let numberOfMIDIOutputs = outputs.size;
 
     // add each of the ports to a <select> box
     outputs.forEach( function( port, key ) {
-      var opt = document.createElement("option");
+      let opt = document.createElement("option");
       opt.text = port.name;
       document.getElementById("outputportselector").add(opt);
     });
 
     // or you could express in ECMAScript 6 as:
     for (let output of outputs.values()) {
-      var opt = document.createElement("option");
+      let opt = document.createElement("option");
       opt.text = output.name;
       document.getElementById("outputportselector").add(opt);
     }