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----')
콘솔. 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加
document.write("

")
假如i=1,以上代码输为
如果想输流为2.jpg,应该这样写
document.write("
 ".jpg)
")