JS判断字符串是否为空或是否全为空格

 1 var test = "   \n   ";
 2 //var test = "      ";
 3 if(test.match(/^\s+$/)){
 4     console.log("all space or \\n")
 5 }
 6 if(test.match(/^[ ]+$/)){
 7     console.log("all space")
 8 }
 9 if(test.match(/^[ ]*$/)){
10     console.log("all space or empty")
11 }
12 if(test.match(/^\s*$/)){
13     console.log("all space or \\n or empty")
14 }