console.log('----1----')
console.log('12' '34')//'1234'
console.log('12' 34 )//'1234'
console.log(12 '34')//'1234'
console.log(12 34 )//46
console.log('----2----')
console.log( '12' '34')//'1234'
console.log( '12' 34 )//46
console.log( 12 '34')//'1234'
console.log( 12 34 )//46
console.log('----3----')
console.log(-'12' '34')//'-1234'
console.log(-'12' 34)//22
console.log(-12 '34')//'-1234'
console.log(-12 34)//22
console.log('----4----')
console.log('12' - '34')//-22
console.log('12' - 34)//-22
console.log(12 - '34')//-22
console.log(12 - 34)//-22
console.log('----5----')
console.log( '12' - '34')//-22
console.log( '12' - 34)//-22
console.log( 12 - '34')//-22
console.log( 12 - 34)//-22
console.log('----6----')
console.log(-'12' - '34')//-22
console.log(-'12' - 34)//-22
console.log(-12 - '34')//-22
console.log(-12 - 34)//-22
javascript中字符串连接的同时数字相加
document.write("
![](images/" i 1 ".jpg)
")
假如i=1，以上代码输出为
如果想输出为2.jpg，应该这样写
document.write("
![](images/" (i 1) ".jpg)
")
![[Web front-end] Node.js quick start](https://img.php.cn/upload/course/000/000/067/662b5d34ba7c0227.png)
