JavaScript 16进制字符串拼接问题
给的指令是
var a = 'aa 55 00 09 01 11 10 ff f2 81 b0 0d 0a'；
通过转译成
var a = '\xaa\x55\x00\x09\x01\x11\x10\xff\xf2\x81\xb0\x0d\x0a'；
发送时没问题的
现在就是 需要对指令中的 某一位 通过程序的形式进行更改，比如 \x09 这一把
我写成
var b = 5;
var str = '\x' + b.toString(16);
var a1 = '\xaa\x55\x00'+ str +'\x01\x11\x10\xff\xf2\x81\xb0\x0d\x0a'；
这样写是不行的
想问下 js 要怎么拼接16进制的字符串
var str = '\x' + b.toString(16);
改为
var str = '\\x' + b.toString(16);
//十六进制字符串转字节数组
function Str2Bytes(str)
{
var pos = 0;
var len = str.length;
if(len %2 != 0)
{
return null;
}
len /= 2;
var hexA = new Array();
for(var i=0; i<len; i++)
{
var s = str.substr(pos, 2);
var v = parseInt(s, 16);
hexA.push(v);
pos += 2;
}
return hexA;
}
//字节数组转十六进制字符串
function Bytes2Str(arr)
{
var str = "";
for(var i=0; i<arr.length; i++)
{
var tmp = arr[i].toString(16);
if(tmp.length == 1)
{
tmp = "0" + tmp;
}
str += tmp;
}
return str;
}
我找到的解决办法
var b = getHex(calculate(a));
var zl = '\xaa\x55\x00\x09\x01'+ b +'\x11\xff\xf1\x0D\x0A';
// 16进制数据对照表
function getHex(e){
var toArray = ['\x00','\x01','\x02','\x03','\x04','\x05','\x06','\x07','\x08','\x09','\x0a','\x0b','\x0c','\x0d','\x0e','\x0f',
'\x10','\x11','\x12','\x13','\x14','\x15','\x16','\x17','\x18','\x19','\x1a','\x1b','\x1c','\x1d','\x1e','\x1f',
'\x20','\x21','\x22','\x23','\x24','\x25','\x26','\x27','\x28','\x29','\x2a','\x2b','\x2c','\x2d','\x2e','\x2f',
'\x30','\x31','\x32','\x33','\x34','\x35','\x36','\x37','\x38','\x39','\x3a','\x3b','\x3c','\x3d','\x3e','\x3f',
'\x40','\x41','\x42','\x43','\x44','\x45','\x46','\x47','\x48','\x49','\x4a','\x4b','\x4c','\x4d','\x4e','\x4f',
'\x50','\x51','\x52','\x53','\x54','\x55','\x56','\x57','\x58','\x59','\x5a','\x5b','\x5c','\x5d','\x5e','\x5f',
'\x60','\x61','\x62','\x63','\x64','\x65','\x66','\x67','\x68','\x69','\x6a','\x6b','\x6c','\x6d','\x6e','\x6f',
'\x70','\x71','\x72','\x73','\x74','\x75','\x76','\x77','\x78','\x79','\x7a','\x7b','\x7c','\x7d','\x7e','\x7f',
'\x80','\x81','\x82','\x83','\x84','\x85','\x86','\x87','\x88','\x89','\x8a','\x8b','\x8c','\x8d','\x8e','\x8f',
'\x90','\x91','\x92','\x93','\x94','\x95','\x96','\x97','\x98','\x99','\x9a','\x9b','\x9c','\x9d','\x9e','\x9f',
'\xa0','\xa1','\xa2','\xa3','\xa4','\xa5','\xa6','\xa7','\xa8','\xa9','\xaa','\xab','\xac','\xad','\xae','\xaf',
'\xb0','\xb1','\xb2','\xb3','\xb4','\xb5','\xb6','\xb7','\xb8','\xb9','\xba','\xbb','\xbc','\xbd','\xbe','\xbf',
'\xc0','\xc1','\xc2','\xc3','\xc4','\xc5','\xc6','\xc7','\xc8','\xc9','\xca','\xcb','\xcc','\xcd','\xce','\xcf',
'\xd0','\xd1','\xd2','\xd3','\xd4','\xd5','\xd6','\xd7','\xd8','\xd9','\xda','\xdb','\xdc','\xdd','\xde','\xdf',
'\xe0','\xe1','\xe2','\xe3','\xe4','\xe5','\xe6','\xe7','\xe8','\xe9','\xea','\xeb','\xec','\xed','\xee','\xef',
'\xf0','\xf1','\xf2','\xf3','\xf4','\xf5','\xf6','\xf7','\xf8','\xf9','\xfa','\xfb','\xfc','\xfd','\xfe','\xff'];
return toArray[e]
}
// 根据16进制字符串判断在对照表中的下标
function calculate(e){
var e1 = e[0];
var e2 = e[1];
var num = '';
var num1 = '';
if(e1 == 'a' || e1 == 'A'){
e1 = 10;
}
if(e1 == 'b' || e1 == 'B'){
e1 = 11;
}
if(e1 == 'c' || e1 == 'C'){
e1 = 12;
}
if(e1 == 'd' || e1 == 'D'){
e1 = 13;
}
if(e1 == 'e' || e1 == 'E'){
e1 = 14;
}
if(e1 == 'f' || e1 == 'F'){
e1 = 15;
}
e1 = parseInt(e1);
if(e2 == 'a' || e2 == 'A'){
e2 = 10;
}
if(e2 == 'b' || e2 == 'B'){
e2 = 11;
}
if(e2 == 'c' || e2 == 'C'){
e2 = 12;
}
if(e2 == 'd' || e2 == 'D'){
e2 = 13;
}
if(e2 == 'e' || e2 == 'E'){
e2 = 14;
}
if(e2 == 'f' || e2 == 'F'){
e2 = 15;
}
e2 = parseInt(e2);
switch (e1) {
case 0:
num = 0;
break;
case 1 :
num = 16;
break;
case 2:
num = 32;
break;
case 3:
num = 48;
break;
case 4:
num = 64;
break;
case 5:
num = 80;
break;
case 6:
num = 96;
break;
case 7:
num = 112;
break;
case 8:
num = 128;
break;
case 9:
num = 144;
break;
case 10:
num = 160;
break;
case 11:
num = 176;
break;
case 12:
num = 192;
break;
case 13:
num = 208;
break;
case 14:
num = 224;
break;
case 15:
num = 240;
}
switch (e2) {
case 0 :
num1 = 0;
break;
case 1 :
num1 = 1;
break;
case 2:
num1 = 2;
break;
case 3:
num1 = 3;
break;
case 4:
num1 = 4;
break;
case 5:
num1 = 5;
break;
case 6:
num1 = 6;
break;
case 7:
num1 = 7;
break;
case 8:
num1 = 8;
break;
case 9:
num1 = 9;
break;
case 10:
num1 = 10;
break;
case 11:
num1 = 11;
break;
case 12:
num1 = 12;
break;
case 13:
num1 = 13;
break;
case 14:
num1 = 14;
break;
case 15:
num1 = 15;
}
return num + num1;
}