Use += in printer

lib/handlebars/compiler/printer.js

@@ -15,10 +15,10 @@ PrintVisitor.prototype.pad = function(string) {
   let out = '';
 
   for (let i = 0, l = this.padding; i < l; i++) {
-    out = out + '  ';
+    out += '  ';
   }
 
-  out = out + string + '\n';
+  out += string + '\n';
   return out;
 };
 
@@ -37,7 +37,7 @@ PrintVisitor.prototype.Program = function(program) {
   }
 
   for (i = 0, l = body.length; i < l; i++) {
-    out = out + this.accept(body[i]);
+    out += this.accept(body[i]);
   }
 
   this.padding--;
@@ -52,20 +52,20 @@ PrintVisitor.prototype.MustacheStatement = function(mustache) {
 PrintVisitor.prototype.BlockStatement = function(block) {
   let out = '';
 
-  out = out + this.pad('BLOCK:');
+  out += this.pad('BLOCK:');
   this.padding++;
-  out = out + this.pad(this.SubExpression(block));
+  out += this.pad(this.SubExpression(block));
   if (block.program) {
-    out = out + this.pad('PROGRAM:');
+    out += this.pad('PROGRAM:');
     this.padding++;
-    out = out + this.accept(block.program);
+    out += this.accept(block.program);
     this.padding--;
   }
   if (block.inverse) {
     if (block.program) { this.padding++; }
-    out = out + this.pad('{{^}}');
+    out += this.pad('{{^}}');
     this.padding++;
-    out = out + this.accept(block.inverse);
+    out += this.accept(block.inverse);
     this.padding--;
     if (block.program) { this.padding--; }
   }