JavaScript去除字符串中的空格

去除字符串中所有空格

function trim(str) {
    return str.replace(/s*/g, '');
}
console.log('=' + trim(' Hello World ! ') + '=');   // =HelloWorld!=

去除字符串中间的空格

function trimMiddle(str) {
    let head = str.match(/^s*S*/)[0];
    let end = str.match(/S*s*$/)[0];
    let middle = str.replace(/(^s*S*)|(S*s*$)/g, '').replace(/s*/g, '');
    return head + middle + end;
}
console.log('=' + trimMiddle('   Hello  World  !   ') + '=');   // =   HelloWorld!   =

function trimMiddle(str) {
    return str.match(/(^s*)|(S+)|(s*$)/g).join('');
}
console.log('=' + trimMiddle('   Hel   l   o  #  $  world  !(  )  h h    ') + '=');   // =   Hello#$world!()hh    =

去除字符串两边的空格

function trimBothSides(str) {
    return str.replace(/^s*|s*$/g, '');
}
console.log('=' + trimBothSides(' Hello World!  ') + '=');  // =Hello World!=

console.log('=' + '   Hello World !   '.trim() + '=');      // =Hello World !=

去除字符串左边的空格

function trimLeft(str) {
    return str.replace(/^s*/, '');
}
console.log('=' + trimLeft('   Hello World!  ') + '=');     // =Hello World!  =

console.log('=' + '   Hello World !   '.trimLeft() + '=');      // =Hello World !   =

去除字符串右边的空格

function trimRight(str) {
    return str.replace(/s*$/, '');
}
console.log('=' + trimRight('   Hello World!   ') + '=');   // =   Hello World!=

console.log('=' + '   Hello World !   '.trimRight() + '=');     // =   Hello World !=